With the development of high-speed digital circuits and broadband communications, higher requirements have been placed on high-speed signal testing technology. As the core component of a sampling oscilloscope, the performance of the sampler directly determines the system bandwidth, and the pulse width of the trigger pulse is a key factor limiting the sampler bandwidth. Therefore, this paper designs a broadband microwave sampler based on ultra-narrow pulse triggering. By cascading a three-stage amplifier circuit with a step recovery diode, pulse waveform amplification and edge compression are achieved, generating a trigger pulse with an amplitude of >7 V and a falling edge of <150 ps. In the sampling gate circuit, short-line reflection technology is employed to further compress the pulse width to the picosecond level. For the comb-like spectral signal output by the sampling, a high-impedance integrating conditioning circuit is designed to achieve signal spreading and holding. Actual measurements show that this narrow pulse can effectively drive the sampler, achieving equivalent sampling within a 30 GHz bandwidth. The output sawtooth waveform envelope is consistent with the input signal, verifying the feasibility of the sampler in broadband microwave equivalent sampling.