Detection device for magnetic field around tower

The invention discloses a detection device for a magnetic field around a tower. The detection device comprises a magnetic field detector, wherein two connection rods are arranged on a side face of a magnetic field detector casing; horizontal hydraulic cylinders are mounted on the connection rods; vertical hydraulic cylinders are mounted at the lower parts of the horizontal hydraulic cylinders; horizontal hydraulic cylinders are fixed on piston rods of the vertical hydraulic cylinders; arc clamping boards are mounted on the horizontal hydraulic cylinders; and the horizontal hydraulic cylinders are connected with bulges of the arc clamping boards. The detection device can move freely on the tower with the magnetic field detector, and is convenient to mount and repair, and detects conveniently; manual working at heights is avoided; the safety is improved; the magnetic intensities at different heights of the tower can be measured automatically; and measurement can be effectively completed.