The invention provides an oscillatory type tidal power generation device which comprises a base, a column, tidal energy-absorbing boards, a power generation oil cylinder, a hydraulic power accumulator, a generator and a power generation hydraulic motor, wherein the column is arranged on the base and at least one swing arm is arranged on the column; the power generation oil cylinder is connected between the swing arm and the column; the tidal energy-absorbing boards are respectively arranged at the two ends of the swing arm; the power generation oil cylinder is connected with the hydraulic power accumulator which is arranged on the column through an oil pipe; the hydraulic power accumulator is connected with the power generation hydraulic motor through an oil pipe; the power generation hydraulic motor, the hydraulic power accumulator and the generator are all arranged on the column; and the power generation hydraulic motor is connected with the generator. According to the invention, a tide-driven hydraulic device is used to drive mechanical energy into electric energy; high-pressure hydraulic oil produced by the oscillation of the tidal energy-absorbing boards can drive the generator to generate electricity by the rotating of the power generation hydraulic motor. The device has simple structure, high reliability, low failure rate and is easy to install and maintain. Not only is the device suitable for high current sea areas, but also suitable for slow flow areas with lower flow rate and shallow sea areas.