Abstract: Gas leakage protection apparatus includes a pressure-differential sealing device and a thermal electricity converting device installed at a burner head for converting the heat of the fire into electric energy which is supplied to a solenoid valve at a bottom of a body to ensure smooth flow of gas through an opening of a gas duct. When the fire is out, the temperature drops so that the converting device cannot supply energy to the solenoid valve, causing the opening to be blocked and gas cut off. The pressure-differential sealing device consists of two interlocking L-shaped connecting tubes. A control element having a small-diameter inner bore and a large-diameter inner bore is disposed in one of the connecting tubes. The wall of the large-diameter inner bore is circumferentially provided with multiple holes. A control rod having a bottom flange fitted with a washer is disposed inside the inner bores of the control element.