The invention provides a portable onsite converter valve tester comprising a converter valve tester. A tester baseplate is arranged below the converter valve tester. The tester baseplate is rectangular. A rectangular sliding sleeve is arranged at both sides of the tester baseplate. Rectangular sliding sleeves are arranged along the length direction of the tester baseplate. Each rectangular slidingsleeve is connected with the tester baseplate through a hinge shaft, and each hinge shaft is provided with a torsion spring which makes the corresponding rectangular sliding sleeve rotate outward allthe time. Each rectangular sliding sleeve is internally provided with a rectangular sliding plate which can slide up and down in the rectangular sliding sleeve. The top end of the rectangular slidingplate is provided with a positioning block, and the positioning block can fall to the top end of the rectangular sliding sleeve. The positive effects of the portable onsite converter valve tester arethat the tester cannot be opened accidentally due to shaking and the like when being transported into the engineering truck, and the service life of the equipment is enhanced and the safety of the operator is ensured.