When the traditional high-g acceleration sensor penetrates the hard multi-layered target, it is easy to cause the overlap of the penetration overload. The rigid body signal is submerged in the vibration signal, resulting in the error of the layer-counting recognition algorithm, and it is difficult to judge the time of the penetration ammunition. Based on the principle of the capacitance sensor and the piezoelectric sensor, a composite sensor for penetration fuze is designed in this paper. On this basis, a layer-recognition algorithm based on capacitance and piezoelectric signal fusion is designed, and its feasibility is verified by software simulation.