The utility model relates to the field of oil production machinery and discloses a double-seal flowback preventing check valve. A central tube is arranged between an upper connector and a lower connector. A piston is arranged outside the central tube in a matched mode. The outer side of the upper connector is connected with an outer sleeve. The outer circumferential face of the piston and the inner side of the outer sleeve are arranged in a matched mode. A spring is arranged between the upper end face of the piston and the lower end face of the upper connector. The lower connector is arranged at the lower end of a conical valve body. The lower end of the outer sleeve is connected with the outer side of the conical valve body. A one-way valve is arranged in a valve housing of the conical valve body. A front passage of the one-way valve is communicated with an outside space of the conical valve body from the side face. A liquid flow passage is formed between the central tube and the end face of the conical valve body. Conical sealing surfaces which are mutually matched are arranged between the piston and the upper end of the conical valve body. A rear passage of the one-way valve is connected with a space which is located below the lower end face of the piston and on the outer sides of the conical sealing surfaces. The double-seal flowback preventing check valve is capable of achieving double sealing, reduces the phenomena of sand burying and sand plugging, prevents flowback, reduces operations caused by leakage and loss of the one-way valve and reduces cost.