The invention relates to a fault-tolerant system of an open-winding three-phase motor and a control method of the fault-tolerant system. The fault-tolerant system comprises an open-winding motor, wherein a common connection point of a star winding is opened, current input ends a, b and c and current output ends x, y and z are respectively connected with inverter working bridge arms Bra, Brb, Brc,Brz, Bry and Brx, the inverter working bridge arms Bra, Brb and Brc and a parallel inverter fault-tolerant bridge arm Bf1 form an inverter I, the inverter working bridge arms Brz, Bry and Brx and a parallel inverter fault-tolerant bridge arm Bf2 form an inverter II. A full-bridge inverter is employed and the two inverter fault-tolerant bridge arms are assisted, a fault point can be rapidly removedwhen a switch fault occurs in the inverter, a system topological structure is changed even under the condition that multiple fault points occur, so that the system still can continuously, safely andreliably run, and the continuous and reliable running of the production process is effectively ensured. The fault-tolerant system has high universality and is applicable to various types of motors.