When the Japanese surrendered in August 1945, the school was still under the control of Kempi Tai. It was not until November that all the Japanese soldiers were captured. Rumours were heard every day about apparitions of the innocent dead.

On 21^st March, 1946, Mr. J. Youngsaye, together with 4 boys, took over the school which had been vacated, after it was inspected by the army commander. The next day, Bishop Hall inspected the school and asked Mr. Youngsaye to act as the Headmaster. However, he declined the offer because he had taken up the offer of Mathematics teaching from D.G.S.. Then, Mr. O. V. Cheung took up the post temporarily. Boy scouts were instructed to act as night guards as it was discovered that many looters came to the school to steal the ammunition left there by the Japanese. Meanwhile, advertisements were published in South China Morning Post and Wah Kiu Yat Po for recruitment and 245 students were admitted.

The new academic year commenced on 11^th September with Mr. Monks, the acting Headmaster, addressing the school in the same DBS tradition as before. However, everything was still in a mess until Mr. Goodban arrived from England on 19^th November. He immediately started the restorations as he resumed his headmastership. Repairs started during the Christmas holidays. It was interesting to discover that many lost desks and chairs were eventually found in La Salle College. Also, benches were made in the Hall so that every student was given a seat during Assembly. Previously only the senior boys had seats. On 30^th March, the remains of the Japanese corpses on the west side of the field were exhumed and removed by the Sanitary Department. In the same year, summer holidays were introduced.

The tuckshop was opened in 1948 while the chapel was moved from the central east wing on the first floor to the present Form 3 corridor. The new House system, named after the former Headmasters, was introduced in 1949 together with the Piercy Challenge Shield. The school yearbook "Steps" was also published in the same year.

In the 1950s, great construction plans including a gymnasium, a Carnegie Hall (the present Art Room) and a science wing were proposed.

Mr. Goodban resigned in 1955 and he was succeeded by Rev. George She. In the academic rink, it was proposed to drop the primary classes because it was discovered that there was not enough space. Finally it was decided that a completely new Diocesan Preparatory School was to be built. Yet, it was not until 1969 that the resolution was affirmed. 

Extra-curricular activities were proposed during this period and the school captured the Senior Choir and the School Orchestra trophies. The idea of starting the School Fete came up in 1956.

The school became a major force in athletics when Mr. Lowcock was appointed as the Headmaster in 1961. With his previous experience in D.B.S., he structured the administration to improve efficiency and more teachers were being appointed to posts with designated responsibilities.

The year leading to the centenary year was a period of recuperation. Typhoon Wanda struck Hong Kong in 1963 and did consideration damage to the school. Later on, a drought followed. Moreover, all of the above took place while the New Wing, the New New Wing, the barbecue pits, the Swimming Pool were being constructed.

The School Centenary was officiated on 27^th January 1969 and a celebration was held together with the introduction of a new blazer badge, which was intended to cut down costs. A Tea-Party was held in which old boys, parents and past staff members were invited to witness the release of one hundred pigeons and the illumination of a 5 x 40 feet neon sign saying ¡¥DBS-100¡¦ on top the main building. In 1973, the April Strike took place throughout Hong Kong, including DBS.

In 1983, Mr. Lowcock announced his resignation due to his poor health. Mr. J. Lai. became his successor. Under his efforts, orators, scholars, athletes and musicians of the school achieved outstanding results in various competitions. Many trophies were brought back to the school as a result.

During his headmastership, renovation and modernization such as the building of the language laboratory, demonstration room, the rewiring of the school, the installation of gas pipes, intercom system and new firm alarm system, the repainting of the school walls, the computerization of the school, and the setup of the computer rooms were performed throughout the school.

Mr. J. Lai retired in August 2000. Mr. Terence Chang, an old boy, gave up his headmastership at another school to take over the leadership in the new term in September.