The invention relates to a method and a system for making a synthetic seismic record, a medium and a device. The method includes the following steps: acquiring the two-way travel time and reflection coefficient of a wavelet on each reflection interface in a geological body; screening the reflection interfaces at each sampling time on a synthetic seismic record; calculating the amplitudes of reflected wavelets from the screened reflection interfaces at a time ts(i) on the synthetic seismic record, and superimposing the obtained amplitudes to get the amplitude at the time ts(i) on the syntheticseismic record; and calculating the amplitudes of sampling points corresponding to all time ts(i) on the synthetic seismic record. A non-convolution wavelet reflection superposition algorithm is adopted in the invention. The problem that forward analysis of seismic response of multiple thin and thick layered geological models with arbitrary stratum thickness cannot be conducted by using a convolution model is overcome. The accuracy of synthetic seismic records is improved.