As two commonly used quinolone veterinary drugs, pefloxacin and fleroxacin residues have attracted great attention, and it is a demand to develop rapid and efficient detection methods. This paper uses Terahertz Time Domain Spectroscopy (THz-TDS) to study pefloxacin and fleroxacin in fish meal feeds matrix. Firstly, 106 compressed samples of pure substances of pefloxacin, fleroxacin, polyethylene and fish meal feed, and binary mixtures of pefloxacin-fish meal feed, and fleroxacin-fish meal feeds with 17 different concentrations were prepared. Secondly, terahertz spectrum measurement and analysis were carried out on all tableting samples. Then, the continuous projection algorithm (SPA) combined with a support vector machine (SVM) and backpropagation neural network (BPNN) were used to establish a qualitative discrimination model to classify and discriminate the mixture of pefloxacin-fish meal feeds and fleroxacin-fish meal feeds. At last, partial least square regression (PLSR), BPNN and multiple linear regression (MLR) quantitative prediction models were established using the absorption coefficient at the characteristic frequency. The results showed obvious absorption peaks of pure pefloxacin at 0.775 and 0.988 THz, and obvious absorption peaks of pure fleroxacin at 0.919 and 1.088 THz. Polyethylene had no absorption of THz wave, and fish meal feeds had no absorption peak. The absorption peaks of two mixtures appeared near the absorption peaks of pure antibiotics. In qualitative discrimination, SVM was the best model, and the accuracy, precision, recall and F1 scores of the prediction set were 97.06%, 97.22%, 97.06% and 97.14%, respectively. In the quantitative regression, SPA-BPNN was the best model for predicting pefloxacin-fish meal feeds, with correlation coefficient (R_p) and root mean square error (RMSEP) of prediction set being 0.984 9 and 0.009 5 respectively, and SPA-MLR was the best model for predicting fleroxacin-fish meal feeds, with R_p and RMSEP being 0.982 7 and 0.040 6 respectively. This study shows that THz-TDS technology is feasible for qualitative and quantitative detection of pefloxacin and fleroxacin in fish meal matrix, which provides theoretical and technical reference for practical detection of pefloxacin and fleroxacin in the livestock and poultry industry.