The invention discloses a zero-fire line communication automatic adjusting circuit and a control method thereof. The circuit includes: switching devices Q1, Q2, Q3, Q4; Q1 is arranged between the fireline L and the neutral line L/N, Q2 is arranged between the fire line L and the neutral line N/L, Q3 is arranged between the neutral line N and the neutral line N/L, and Q4 is arranged between the neutral line N and the neutral line L/N. The zero-fire line detection circuit is connected with the fire neutral line L/N for detecting whether the connection mode of the fire neutral line L/N is correct. When the neutral detection circuit detects that the neutral is inverted, the control drive circuit drives Q1 and Q3 to turn off and Q2 and Q4 to turn on. The invention realizes automatic detectionof zero-fire line reverse connection in internal and external zero-fire line communication. It has the function of automatically adjusting the zero-fire wire connection without manual adjustment. A relay is added on the zero-fire line in the zero-fire line adjustment process to avoid short circuit of the zero-fire line. The control method of the invention is safe and reliable.