The utility model relates to a pipeline inspection device field discloses a detect in pipeline with detection device in mileage measurement mechanism and pipeline magnetic leakage, and wherein mileage measurement mechanism includes the base and fixes the pillar in base one side center department, has at least two sets of mileages wheel measurement element along the circumference equipartition on the base, and mileage wheel measurement element passes through the rotatable setting of support shaft on the base, and the mileage wheel measurement element set up with the pillar homonymy, spring coupling is passed through to the pillar on to mileage wheel measurement element's one end, and under the normality, the spring is in tensile state, and masterpiece that the spring produced is used in that mileage wheel measurement element goes up so that mileage wheel measurement element pastes tight pipe wall at the operation in -process. The utility model provides a detecting in the pipeline and adopting circumference mileage wheel overall arrangement form with mileage measurement mechanism, the axial of comparing in prior art sets up the overall arrangement mode that the multiunit mileage was taken turns for the whole size of mechanism has great reduction, can adapt to the pipeline that the pipe diameter is littleer, uses more extensively, convenient.