OBJECTIVE： To study the affinity of penehyclidine optical isomers to muscarinic （M） receptor subtypes， and provide reference for revealing the action targets and efficacy selectivity of penehyclidine. METHODS： Homology modeling， molecular docking and other molecular simulation technologies were used to analyze and predict the binding energy of 4 optical isomers to M receptor subtypes and judge its affinity by comparing the binding energy of different optical isomers R1 （3R， 2′ R）， R2 （3R，  2′ S）， S1 （3S， 2′ R）， S2 （3S， 2′ S） with M receptor subtypes M1-M5. RESULTS： All the 4 optical isomers can dock into the active sites of M receptor subtypes， and different optical isomers showed great differences in the molecular docking with different M receptor subtypes. Penehyclidine isomers showed larger binding energy to M3， the binding energy of 4 optical isomers ranged in 5 736.519-5 907.143 kcal/mol. The binding energy of R1 to M1 was 1 190.041 kcal/mol； while those of other optical isomers to each receptor subtype were lower or negative. CONCLUSIONS： R1 shows the affinity to M1 receptor. And all the 4 optical isomer show the affinity to M3.