The invention belongs to the technical field of Raman scattering, and discloses an asymmetric weighted least squares based Raman spectrum detection baseline correction method. The method includes, fora Raman spectrum to be fitted to a baseline, setting smoothing parameters and an iteration termination condition, initializing weight into unit matrixes during first iteration, and obtaining an initial fitting baseline through minimizing penalized least squares; and performing updating on the weight through a softsign function according to the difference signal between an original spectrum and the fitting baseline, the process being repeated continuously until a termination condition is met. The original Raman spectrum subtracts the final fitting baseline, so that baseline correction of the Raman spectrum can be realized. Correction can be performed on the original Raman spectrum by utilizing the method, so that spectrums after baseline correction can be closer to real Raman signals, theaccuracy of Raman spectrum detection can be enhanced, and the method has important practical significance for the quantitative analysis and applications of the Raman spectrum.