[Aim] In order to identify the safety of pyraclostrobin in Citrus maxima and the effect of bagging on pesticide residues, a study on the residual degradation dynamics of pyraclostrobin was conducted. [Method] Pyraclostrobin was sprayed on C. maxima at two dosages with bagging and no-bagging in a field experiment, and then residues were determined by HPLC-MS/MS. [Result] Results showed a good linear relationship (r²=0.9993) in the concentration range of 1-500 μg·L^-1 for pyraclostrobin, the detection limit of pyraclostrobin was 0.7 μg·kg^-1. When the spiked levels were 2, 50 and 1000 μg·kg^-1, the average recovery rates of pyraclostrobin varied between 83.8% and 105.8%, with relative standard deviation (RSD) ranging from 2.9% to 9.1%. Therefore, the method met the detection requirement. The residual degradation dynamics of pyraclostrobin followed the first-order kinetic equation. The half-life (T_1/2) of pyraclostrobin was 5.10-5.26 d in the bagging treatment, and 4.48-4.79 d in the no-bagging. [Conclusion] The half-life (T_1/2) of pyraclostrobin was slightly longer in the bagging treatment, the residues of pyraclostrobin in C. maxima were all not detected after 65 days.