Objective:To explore the feasibility of the maze design of a proton therapy system.Methods:According to the construction scheme of a medical proton therapy system, the ambient neutron dose equivalent rate outside the maze entrance was estimated by numerical analytical formula, and compared with the monitoring result.Results:The ambient neutron dose equivalent rate was estimated at between 3.85×10 -2 μSv/h and 7.57 μSv/h and measured to be ≤1.56 μSv/h. Conclusions:The maze entrance was designed to have 5 sections of tunnel for cyclotron room and 3 sections of tunnel for treatment room, respectively, each with designated length and width. The levels of ambient dose equivalent rate outside the maze entrance is acceptable.