The invention relates to an automatic cut-off valve for accidental explosion and leakage of a natural gas pipeline. The automatic cut-off valve is characterized by comprising a shell, wherein the shell is provided with a gas inlet passage and a gas outlet passage, which are communicated with each other; a left cylinder block and a right cylinder block are installed above the gas inlet passage and the outlet passage, and the front cylinder block and the right cylinder block are respectively provided with a piston which is identical in structure; the periphery of each piston is provided with an anti-leakage sealing rubber gasket; a lift-type drawing-bar valve core with a sealing rubber gasket is installed on the central position of the bottom of each piston, and each lift-type drawing-bar valve core is inserted into a valve seat in a matching manner; a starting drawing bar is installed on the central position above each piston, and the starting drawing bar stretches out of the outer end of a cylinder cover; a pressure spring is installed between the cylinder cover and the piston; a ventilation hole is formed in an appropriate position of the left corner and an appropriate position of the corner of the left cylinder and the right cylinder; an armature piece is also installed above each cylinder cover and matched with permanent magnet in a starting handle.