The integration of radar and communication is conducive to improving the utilization rate of hardware resources and spectrum,and alleviating the phenomenon of spectrum congestion,which has become a research hotspot in recent years.The integrated signal modulated by direct information has high side lobe,and the integrated signal modulated by spread spectrum has large bandwidth.To solve the problems,an integrated waveform optimization method with weighted preprocessing is proposed.This paper analyzes the ambiguity function of multi-symbol Orthogonal Frequency Division Multiplexing integrated signal and the effect of correlation function on the ambiguity function,and utilizes the Whale Optimization Algorithm to select the weighting coefficients to improve the auto-correlation and cross-correlation performance of the original sequence,and then optimizes the peak sidelobe ratio performance of the ambiguity function.Simulation results show that:1) The proposed integrated waveform design method has a smaller bandwidth and the peak sidelobe ratio performance is further optimized;and 2) The communication rate and bit error rate performance satisfy the communication requirements,which makes it suitable for the integration of radar and communication.