The invention provides a flushing protection gas anchor. A check valve is mounted inside a bypass flow joint; the upper part of an inner tube is connected with the bypass flow joint; the upper part of an outer tube is threaded to the lower part of the bypass flow joint; an annular cavity is mounted between the inner tube and the outer tube; the lower part of the outer tube is connected with a lower joint; the lower part of the inner tube is inserted inside the lower joint; a linking hole is arranged at the lower part of the outer tube; a radial runner and a vertical runner are arranged on the bypass flow joint; a liquid inside the inner tube can flow to the radial runner; the annular cavity is communicated with the vertical runner; an oil-gas mixed liquid flows out from the radial runner on the bypass flow joint through the check valve, and flows downward after being turned; the oil-gas mixed liquid enters the annular cavity between the inner tube and the outer tube through the linking hole at the lower part of the outer tube, flows below an oil suction pump through the vertical runner, and is extracted out from the oil suction pump; when the oil-gas mixed liquid flows downward in a steering manner, the gas is separated, so that the effect of the gas anchor can be realized; gas flows upward in an oil sleeve annular space, and the liquid flows downward, so that gas can be prevented from entering a pump to influence the effects of the pump; and under the effects of the check valve, the flushing liquid cannot enter a ground layer without polluting an oil layer or deadly pressing the oil layer.