The current transients calculation software in hydraulic generating unit was developed only for a particular type of hydropower stations , flexibility is not enough and lack of visual . so the software was developed for transients calculation in hydraulic generating unit based on MATLAB in the paper , it is used for simulation of hydropower stations with all part models, model addition and modification is convenient , and it can be configured according to the actual situation of different plants , it has many functions , such as calculation of great fluctuation process, slight fluctuation process, hydraulic disturbance process, combination conditions process , it is used for simulation of different kinds of hydropower stations .Example analysis shows that calculation results and the actual plant coincided basically with the experimental results, and it can provide effective basis for proper regular of guide vane closure and proper regulation parameter of PID.