The invention relates to an ultrasonic detection coupling oil pot for nuclear power equipment. The oil pot comprises a storage part, a control part, a seal head part and a brush head part. According to the oil pot, when the ultrasonic detection is carried out on a large-size weld joint, coupling oil is smeared around the weld joint through an oil pot with a brush head, the oil is uniformly smeared, oil liquid flow is not prone to form, the working efficiency can be improved, the radiation damage on operators is reduced, and the health of the operators is guaranteed.