The invention relates to a dynamic potential detection circuit for a DC motor. The detectable quantity obtained by conventional equipment cannot reflect the dynamic process of the detected physical quantity and has poor real-time. The dynamic potential detection circuit comprises a DC motor armature electric quantity detection circuit and a dynamic potential operation circuit, wherein the DC motor armature electric quantity detection circuit comprises an armature winding M1 of the DC motor, and the positive end A+ of the armature winding is connected with the Ud end of a connecting piece CN1 and one end of an upper divider resistor R2 respectively; the negative end A- of the armature winding is connected with one end of a microinductor L1 and one end of a potential positive input resistor R4 respectively; and the dynamic potential operation circuit comprises a potential operational amplifier U1, a current operational amplifier U2 and a superposition operational amplifier U3. The dynamic potential detection circuit has the advantages of simple circuit structure, strong generality and low cost.