The seismic design of nuclear equipment is an important topic in the field of earthquake mitigation for nuclear power plant. In order to solve the issue of simulating design ground motions for nuclear equipment with representative response spectrum (RRS) compatible and standard power spectrum density (PSD) enveloped, an innovative method based on the recommended method from 2014 version of Standard Review Plan (SRP) is proposed considering iterative correlation and phase-angle spectrum. The artificial ground motion synthesis with RRS compatible and standard PSD enveloped is accessed by controlling Fourier amplitude in traditional frequency-domain method, providing a decent test basis for the selection of input artificial earthquakes. Pressure vessel is selected as the prototype for seismic research of nuclear equipment. Through shaking table test and comparing the intensity measures and PSD of acceleration time-series of model responses, it is verified that ground motion with both RRS compatible and standard PSD enveloped stimulates greater seismic responses on the structure, indicating the significance and importance of the requirement of enveloping PSD in deign ground motion simulation