The invention provides a series-parallel connection six-degree-of-freedom active wave compensation platform which comprises a first compensation system, a second compensation system and a third compensation system. The first compensation system comprises a base fixed to a hull, a first compensation platform, a first hydraulic cylinder, a second hydraulic cylinder, a third hydraulic cylinder and amiddle electric cylinder, wherein the first hydraulic cylinder, the second hydraulic cylinder and the third hydraulic cylinder are fixed to the base, and one end of an inner cylinder of each of the first hydraulic cylinder, the second hydraulic cylinder and the third hydraulic cylinder is connected to the first compensation platform; and a universal connector is arranged at one end of the middle electric cylinder and connected with a torsion motor, and the torsion motor is fixed to the first compensation platform. The invention further provides a compensation method of the series-parallel connection six-degree-of-freedom active wave compensation platform. By the adoption of the provided series-parallel connection six-degree-of-freedom active wave compensation platform, the hydraulic cylinders, electric cylinders and sensors are used for solving a compensation problem, the structure is simple and reasonable, six-degree-of-freedom compensation can be simplified into compensation of the three compensation systems, the three compensation systems separately work, cooperate and are correlated, the problem is simplified, and meanwhile a compensation effect is enhanced.