Inner surface defect expansion inspection tool for steel pipe

The utility model provides an inner surface defect expansion inspection tool for a steel pipe, which includes a main body neck-shaped wheel and a telescopic handle, wherein a mud box and a threaded hole connected with the main body are processed on the circumference of the neck part of the main body neck-shaped wheel, so that the mud box can be fixed at the neck part of the main body neck-shaped wheel; and at the two flange ends of the main body neck-shaped wheel, an eye bolt is arranged at one end of the main body neck-shaped wheel, and a handle with the threaded hole is arranged at the center of the other end of the main body neck-shaped wheel. The utility model has the effects that the novel expansion inspection tool can rotate on an inspection rack through the steel pipe, can be used for defect expansion inspection for a pull concave, an inner edge and an inner straight passage on the inner surface of the steel pipe through utilizing the characteristics of soft materials such as plasticine and the self we