The sliding mode control with unidirectional auxiliary surfaces (UAS-SMC) based on the power reaching law was used for a class of nonlinear continuous systems.According to the nonlinear continuous system, a UAS-SMC was designed.On which basis, the power reaching law was introduced, and a UAS-SMC based on power reaching law was developed.Then, theoretical analysis proved that the system states will converge on the switching surfaces in a finite time and it is stable.The simulation results show that the chattering can be effectively reduced, and the method ensures the reaching speed near the switching surfaces.The reaching law is zero if and only if the system states are zero.