For investigating the effect of cyclic loading waveforms on deformation of structural soft soil，we take the marine soft soil of Lingang industrial area in Tianjin Binhai new area as the research object，carry out the cyclic loadings with varying waveforms and amplitudes to the samples，research the dissipated energy curves of structural soft soil are researched under cyclic loadings with varying waveforms and amplitudes，and propose the evolution equations in two cases. The results show that when the effect of the loading waveform is considered，the cumulative plastic strain develops slowly，and the change of the waveform has little effect on the development trend of plastic strain when the loading amplitude is below the threshold stress，for example，30 kPa. When the amplitude is much higher than the threshold，for example，40 kPa，60 kPa，and 80 kPa，the cumulative plastic strain increases rapidly，the rate of deformation for the square wave is fastest，and the sinusoidal wave comes the second，while the triangular wave is the last.