Abstract: In the Dual-computer Hot-backup working pattern of micro-satellite,if the on-board computers work in parallel,it can improve the efficiency of the system.According to the actual tasks of micro-satellites,a scheduling method based on genetic algorithms was presented to reduce tasks time consumption and balance the load in the onboard computers.However,reducing tasks time consumption and balancing load are incompatible in some cases.In the fitness function of genetic algorithms,the parameters of reducing tasks time consumption and balancing load were considered,quantized and assigned with the same weighted value.By this way the comprehensive performance of the Satellite Keeping Operator(STO) was improved.