For an ideal pulse pileup situation, this paper establishes a triangle-trapezoid dual-channel shaping algorithm by analyzing the correlation between trapezoid and triangle shaping results. In this model, the effective pulses in many pulse pileup situations are preserved, which greatly improves the count rate of the pulse spectra. In this paper, the pulse acquisition process is modeled in MATLAB. The input of the model is the negative exponential decay pulses obtained by discrete direct sampling of the actual spectra, and the effectiveness of the optimization algorithm is verified by inputting different levels of pulse pileup signals. The results show that the improved triangle-trapezoid dual-channel shaping algorithm can more accurately retain the effective pulse values under pulse pileup, improve the count rate of the spectra, and ultimately improve the resolution of the pulse spectra.