Communication signals are vital to the implementation of integrated radar and communication, which is an effective way to reduce platform volume and electromagnetic interference. In this paper, an integrated radar and communication signal based on multicarrier parameter modulation chirp signal is proposed. Its main carrier adopts the unique chirp signal to implement radar function, while communication information is modulated by the subcarrier with different chirp rates and initial frequency chirp signal. The signal property is analyzed by ambiguity function, and the processing and system performance are studied. Finally, simulation results demonstrate that the proposed sharing signal has a low symbol error rate and high robustness, and communication data transmission can be implemented by slightly degrading the radars performance.