Abstract: Due to the non-uniform distribution of acoustic parameters, such as sound velocity and density, caused by the irregular shape of the skull, focus shift could happen while using the traditional phase-controlled focusing method for transcranial ultrasound focusing. The time reversal method is considered to be able to overcome the difficulty of skull nonuniformity, and can be an effective means to achieve transcranial focusing. However, when the traditional finite element and finite difference methods are used for numerical simulation of transcranial ultrasound focusing, very precise grids need to be divided for calculation, which consumes a lot of time. The K-space pseudo-spectrum method is used to solve the acoustic wave equation by performing the Fourier transform in the space domain and the finite difference in the time domain, which can greatly reduce the grid density required for calculation while ensuring the accuracy of calculation. In this article, the Matlab K-wave open source toolbox and the CT data of cynomolgus monkey skulls are used to realize transcranial ultrasound focusing based on the time reversal method, and the problem using the time reversal method to compensate the focus shift caused by the irregular skull shape and the non-uniform sound velocity is discussed. The simulation results show that K-wave can serve accurate transcranial ultrasound focusing while improving the computing speed. Compared to traditional phased focusing methods based on acoustic time difference method, the time reversal method has higher focus intensity, more regular focal spot shape, and better focusing effect at preset focus positions.