The invention discloses a gas-proof method for area grouting combined with anti-seepage and protecting in the process of a tunnel passing through a coal bed. The gas-proof method comprises the following steps that a first gas isolating ring is excavated on the initial position of uncovering coal of the tunnel after the tunnel passes through the coal bed gathering with gas and the trend of the coal bed is determined, circumferential grouting is conducted, an airtight agent is mixed into grout, and a first area grouting belt is formed; fast setting concrete mixed with the airtight agent is sprayed into a tunnel-zone section passing through the coal bed in the process of passing through the coal bed, a gas sealant is sprayed on the surface of the concrete, a gas isolating plate is constructed, and an anti-seepage and protecting zone is formed; and a second gas isolating ring is excavated on the ending position of the uncovering coal of the tunnel, circumferential grouting is conducted, the airtight agent is mixed into the grout, and a second area grouting belt is formed. The gas-proof method for area grouting combined with anti-seepage and protecting in the process of the tunnel passing through the coal bed has the beneficial effects that the gas can be isolated in the coal bed, diffusion of the gas to a non-coal-bed gas active area is decreased in the construction period, and the risk of penetration and diffusion of the gas in the stratum to the tunnel is decreased in the tunnel operating period.