The invention discloses a single-way A/D conversion temperature regulator and a realization method thereof. The single-way A/D conversion temperature regulator is connected with a temperature controller and comprises a temperature sensor R for detecting the indoor temperature and a variable resistor W for setting the desired indoor temperature; the temperature sensor R is in series connection with the variable resistor W; the variable resistor W is in parallel connection with a normally open switch K. According to the single-way A/D conversion temperature regulator and the realization method thereof, provided by the invention, the normally open switch K is arranged at the two ends of the variable resistor W, the temperature regulator and the temperature controller are connected only by one guide line arranged therebetween, the temperature controller only occupies one input/output port, the circuit structure is simple, the occupancy of resources is reduced, only one line needs to be laid indoors during assembling, therefore the line installing and using cost is greatly reduced.