The invention relates to a combined optical fiber EFPI broadband PD ultrasonic detection system. The system comprises a light source, an optical fiber 1 / 2 optical splitter, an optical fiber, an optical fiber coupler, a first optical cable head, a first 16-core optical cable, a second optical cable head, an optical fiber EFPI sensing combined probe, a third optical cable head, a second 16-core optical cable, a fourth optical cable head, a multi-path photoelectric detector, a first coaxial cable, a broadband signal superposition and amplification device, a second coaxial cable and a high-speed data acquisition device. Compared with the prior art, the system has the advantages that the problem that an EFPI sensor working at the existing resonant frequency can only be used for narrow-band measurement of ultrasonic signals is solved, and the frequency band requirement of the partial discharge ultrasonic signals of 20 kHz to 500 kHz is met.