Abstract: Being quite overelaborate, rail tanker measurement is subject to considerable errors which give rise to economic losses to refineries and customers. The error-causing factors are th following: ① Inaccurate hand-dipping; ② Large deviation of measuring temperature; ③ Non-standard density measuring technique; ④ Perfunctory strapping table for rail tanker; ⑤ Incorrect table consultation, table filling in and calculation; ⑥ Thermal expansion and contraction of the loaded tanker; ⑦ Transverse deformation of the tanker after being loaded; ⑧ Large error in tanker volume verification (the main factor for inaccurate tanker measurement). Precautions are given accordingly in the light of the specific link where the errors occur. It is pointed out that most foundmental solution to the correction of rail tanker measurement errors is to adopt the computer measurement technique of dynamic electricity rail balance, by which multiple measurement errors can be turned into one weight difference, and an accuracy of 0.2 degree can be achieved.