The approach to control the turbine power during engine start-up for staged combustion cycle engine using an oxidant rich gas generator is described in this paper. The primary parameters which control turbine power are GG temperature and turbine pressure ratio. The GG temperature control can be realized by regulating the flow regulator start-up flow rate, the start time from start-up to main stage and the regulator operating condition transfer rate. By choosing the main fuel valve opening time and the mixture ratio control valve (MRV) conversion time to larger mass flow, the combustion chamber ignition time and the peak value of chamber pressure are controlled. By this method, the turbine pressure ratio can be controlled during engine start-up process. The influence of the above methods on start-up characteristic is analyzed by numerical simulation.