The utility model relates to a coil of strip shearing technology field provides a clearance automatically regulated control system and lead screw drive structure, which comprises a bracket. The lead screw, the at least one end of lead screw sets up the transmission shaft, rotary encoder, rotary encoder rotates the hookup with the transmission shaft, rotary encoder is fixed in on the support, compare traditional displacement sensor with by regulating part surface contact, the adoption of this application embodiment is applied to the lead screw drive structure on the automatically regulated equipment of clearance, the lead screw axial sets up the transmission shaft rather than an organic whole, the transmission shaft passes through spring shaft coupling and rotary encoder hookup, structure itself can obtain the measured value of an accuracy, and then solved traditional displacement sensor and receive external disturbance when being measured by regulating part surface contact easily and influence its survey numerical value of a quantity, and then the two circle shears of influence carry out gap amount's regulation, reach accurate measurement lead screw turned angle parameter, effectively guaranteed the measuring accuracy.