The invention provides a circuit for converting sensing resistance into digits. The circuit comprises multiple current sources, multiple controlled switches, a switch S1, a switch S2, a resistor R1, a resistor R2, a switch S3, a switch S4, a switch S5, a switch S6, a comparator I5, a first counter, a second counter and a decoder, wherein one end of each current source is connected to the ground, the other end of each current source is connected with one end of the corresponding controlled switch, and the other end of the corresponding controlled switch is connected with one end of the switch S1 and one end of the switch S2; the other end of the switch S1 is connected with one end of the resistor R1; the other end of the resistor R1 is connected with a power port; the other end of the switch S2 is connected with one end of the resistor R2; the other end of the resistor R2 is connected with the power port. The circuit disclosed by the invention has the advantages that simpleness and effectiveness are realized, the area of a distribution map is small, the accuracy is high, and multiple extensible initial register comparison threshold values can be realized by adopting the combination of multiple resistors; the circuit can work under different power voltages without affecting a final result.