Large-area floor flatness detection device and detection method thereof

The invention discloses a large-area floor flatness detection device, and the device comprises a laser transmitter which is used for transmitting laser to form elevation light; the movable chassis is used for being supported on a to-be-tested terrace; the detection assembly comprises a movable rod and a laser receiving disc arranged on the movable rod, the movable rod is installed on the movable chassis in an up-down sliding mode, the bottom of the movable rod makes contact with the ground, and an annular reflective belt used for reflecting elevation light is arranged in the circumferential direction of the laser receiving disc; the width value of the annular reflective tape is equal to the qualified tolerance range value of the flatness required by the to-be-measured floor; the telescopic push rod is connected with the movable chassis through a spherical hinge; the detection speed can be improved, and areas with unqualified flatness on the terrace can be quickly screened out; the invention further discloses