The invention provides a 2-vote-2 alternating current continuous type track circuit and a detecting method of the 2-vote-2 alternating current continuous type track circuit. The track circuit comprises an impedance adjusting circuit, a first isolator, a second isolator, a first voltage adjusting circuit, a second voltage adjusting circuit, a first AD converter, a second AD converter, a first CPU, a second CPU and a third isolator. The invention further provides the detecting method of the 2-vote-2 alternating current continuous type track circuit. The impedance adjusting circuit imitates the impedance features of a traditional 480 relay, so that it is guaranteed that the impedance adjusting circuit is compatible with a traditional alternating current continuous type track circuit. The 2-vote-2 structure is adopted, two independent calculation channels which are isolated from each other are provided, and through analysis of a sampling result of the track voltage, the detection level of the shunting sensitivity is improved. The 2-vote-2 alternating current continuous type track circuit can replace the traditional 480 relay and effectively improve the anti-lighting performance and the safety of the track circuit.