Herein, a broadband chaotic signal generator with a bandwidth of 50 GHz is designed and developed, based on the perturbation of amplified spontaneous emission (ASE) noise in conjunction with semiconductor laser mutual injection. The generator primarily contains two distributed-feedback semiconductor lasers (DFB-SL) and one semiconductor optical amplifier (SOA). Chaotic laser is obtained by perturbing the SL with ASE noise generated by the SOA. In addition, the beating effect caused by the SL mutual injection is exploited to achieve spectrum shaping and bandwidth enhancement. With a feedback strength of 9.096%, frequency detuning of 32.75 GHz, and coupling strength of 1.966, the chaotic laser with a bandwidth exceeding 50 GHz, flatness of ±2.5 dB, and linewidth of 0.56 nm is generated by the signal generator. This broadband chaotic signal generator, with large bandwidth and high flatness, solves the problems of uneven spectrum and narrow bandwidth of chaotic lasers, and further promotes the industrial application of chaotic laser.