The invention discloses a doubly fed generator system with a protector, as well as a method used for protecting the system. The doubly fed generator system with the protector comprises a doubly fed induction generator (100), a rotor side converter (130), an intermediate DC side converter (110), a grid side converter (120) and a bypass protecting circuit (200), wherein the bypass protecting circuit (200) comprises current limiting resistors (R1, R2 and R3) and thyristors (Q1, Q2, Q3, Q4, Q5 and Q6), the thyristors are divided into three groups, each group comprises two thyristors reversely connected in parallel, and is connected with one current limiting resistor in series, and the three groups of thyristors are connected into a star shape; when the voltage of the intermediate DC side converter (110) exceeds the set threshold U2, the thyristors (Q1, Q2, Q3, Q4, Q5 and Q6) are triggered to be conducted. The invention has the advantages of low cost, simple control and stronger fault ride-through capacity.