Multi-point seismic oscillation synthesis method and system

The invention belongs to the related technical field of seismic oscillation detection, and discloses a multi-point seismic oscillation synthesis method, which comprises the following steps: S1, acquiring a power spectral density function at a bedrock; S2, simplifying a soil layer on the bed rock into a homogeneous soil layer which is horizontally layered to acquire a transfer function from a bed rock to the homogeneous soil layer; S3, according to the power density function of the bedrock and the transfer function of the homogeneous soil layer, obtaining transfer functions of the homogeneous soil layer from each point of the bedrock in the X, Y and Z directions, and further obtaining a self-power spectral density function and a cross-power spectral density function of the homogeneous soillayer; and S4, synthesizing the seismic oscillation acceleration of the homogeneous soil layer according to the self-power spectral density function and the cross-power spectral density function of the homogeneous soil layer.