The utility model discloses a profile detection device which may perform rapid and firm position of a profile detection block during vehicle bottom integral profile detection, and overcomes defects that the prior art is quite inconvenient in positioning the profile detection block and cannot guarantee stable positioning during the vehicle bottom profile detection. The profile detection device comprises a pedestal, wherein a vertical strip-shaped groove is disposed in the pedestal; a sliding seat is disposed on the pedestal; a profile detection block is disposed at the top of the sliding seat; a guide rod stretching into the strip-shaped groove is disposed on the sliding seat; the guide rod is slidably connected with the pedestal through the strip-shaped groove; and the sliding seat is provided with a fixing device which is used for fixing the pedestal and the sliding seat. The profile detection device is suitable for applicable occasions of a conventional profile detection device, and has the advantages that the abutting operation of the profile detection device with a vehicle body is simple and the profile detection device can fully guarantee stable positioning after the sliding seat sliding in place.