The invention relates to an oil sampling nozzle wrench assembly which comprises a main body, wherein the main body is a cylinder; a screw hole connected with an oil nozzle screw in a sleeving manner is formed in the center of the main body; top holes are formed in the upper end face of the main body on sides of the screw hole along the circumference of the upper end of the main body at equal intervals; oblique inserting rods are inserted into the top holes; insertion holes are formed in the lateral circumference surface of the main body at equal intervals; and inserting rods are interested into the insertion holes. With the adoption of the oil sampling nozzle wrench assembly, the problem of oil leakage caused by the reasons that a sampling valve oil nozzle cannot be rotated continuously because a mounting position space of the sampling valve is narrow and a sealing drainage rubber pipe influences during sampling when the sampling valve is opened or closed by a common wrench in an oil-immersed power transformer oil sampling process is solved. Further, poor sampling leakproofness and air moisture invasion are prevented, the test data accuracy is improved, unnecessary oil sampling tracking work caused by the reasons is reduced, the problems of misjudgment and missed diagnosis of failures in a transformer are solved and safe and stable running of a power grid and equipment is guaranteed.