The invention discloses a valve flap structure and a double-flap type check valve. The valve flap structure comprises a fixed shaft, a first valve flap, a second valve flap and an isolation assembly. The first valve flap and the second valve flap are provided with a first shaft lug and a second shaft lug. The first shaft lug and the second shaft lug are both arranged on the fixed shaft in a sleeving mode. The second shaft lug is located above the first shaft lug. The isolation assembly is connected to the part, between the first shaft lug and the second shaft lug, of the fixed shaft in a sleeving mode, the top of the isolation assembly supports the second shaft lug, and a gap is reserved between the bottom of the isolation assembly and the first shaft lug; or the side wall of the first valve flap is provided with a first top shaft lug and a first bottom shaft lug, the side wall of the second valve flap is provided with a second top shaft lug and a second bottom shaft lug, the second top shaft lug is located above the first top shaft lug, the second bottom shaft lug is located above the first bottom shaft lug, and the isolation assembly is arranged between the first bottom shaft lug and the second bottom shaft lug. The double-flap type check valve comprises the valve flap structure. The isolation assembly transmits the gravity of the second valve flap to a valve body. The first valve flap does not bear the gravity of the second valve flap. When the valve is opened or closed, the torque needed by the first valve flap is reduced.