Abstract: For improving communication system power efficiency and spectrum efficiency, an orthogonal Prolate Spheroidal Wave Functions (PSWF) pulse modulation method is proposed. The system power efficiency can be improved by using PSWF with high energy concentration degree as transmission pulse. Orthogonal pulse sets is constructed to transmit information based on PSWF, which is orthogonal in time domain and overlapped in frequency domain. As a result, the bandwidth can be reduced and the spectrum efficiency improved. The theory analysis and simulation results show that the system bandwidth efficiency can be fast closed to 2 Baud/Hz and the modulated signal has high energy efficiency in frequency domain which is important to improve power efficiency and reduce electromagnetic interference on other users.