A novel, sensitive and specific screening method for trace multi-residues of 13 β-agonists in porcine urine by combining atmospheric solid analysis probe (ASAP) source with tandem mass spectrometry (MS/MS) has been developed. Optimization experiments were carried out including the selection of solvent, probe temperature and monitoring ionic pairs. Using ASAP combined with rapid solid-phase extraction (SPE) procedures, not only the matrix interference of porcine urine was decreased, but also the sensitivity of the method was improved. Under the optimal conditions, the performance of the proposed method was studied. The linear correlation coefficients (R²) of calibration curves for 13 β-agonists were above 0.98 in the concentration range of 0.5 ng mL⁻¹ to 300 ng mL⁻¹. The limits of determination (LOD) for all target compounds were below 0.20 ng mL⁻¹, recoveries of the developed method for different spiked concentrations varied from 58.5 to 85.7%. A single run for the analysis of 13 β-agonists in a urine sample was achieved within 1.0 min for ASAP-MS/MS detection. In addition to the fast analysis speed, MS/MS provided structural information for the confirmation of target analytes. Real porcine urine samples were investigated and the results were in accordance with the confirmatory determination results by using China’s agricultural industry standard method. The developed method can potentially be used for the screening of 13 β-agonists in porcine urine for the surveillance of livestock.