A method of generating broadband dual-linear frequency modulation signal microwave waveforms (DCMWs) based on monolithic integrated laser is proposed and verified by simulation. In this scheme, under the appropriate bias current, the integrated mutual injection semiconductor laser enters the P1 state, and then the linear frequency modulation signal is directly modulated to the front-end laser. In the simulation experiment demonstration, three kinds of DCMWs in the frequency range of 5~9 GHz are obtained, and the time bandwidth product (TBWP) reaches 800. The full width at half maximum (FWHM) of the three kinds of DCMWs are all less than 0.34 ns, and the peak sidelobe ratio (PSR) is higher than 15.1 dB. The scheme has the advantages of high integration, simple structure and easy regulation.