The utility model discloses a three-cavity layering collection and output oil extraction device. The problems that an existing layering collection and output string is short in service life, high in cost and low in efficiency are solved. A hollow plunger (9) is composed of a big diameter section and a small diameter section. A sleeve is arranged outside an upper pump cylinder to form a clamp chamber, the upper end of the plunger (9) is connected with an upper plunger connector (2) and provided with an upper travelling vale (3), the lower end of the plunger (9) is provided with a lower travelling valve (10), and a lower pump cylinder is connected with a lower connector (12) and provided with an internal fixing valve (11). The upper pump cylinder is connected with an upper pump cylinder connector (1) connected with a first upper oil pipe. The lower connector (12) is connected with a lower oil pipe. The upper end of the sleeve is connected with a second upper oil pipe, and an upper flange at the upper end of the sleeve is connected with the upper pump cylinder. An upper liquid outlet valve (5) is arranged on the upper flange, the second upper oil pipe is connected outside the upper pump cylinder through a variable-diameter connector (4), a lower flange at the lower end of the sleeve is fixedly connected with the lower pump cylinder, and an external fixing valve (8) is arranged on the lower flange.