Disclosed is an electro-hydraulic actuator of a spherical pump for a robot. Two oil feeding and discharging openings (121) for oil feeding and discharging are formed in a cylinder cover (101) of the spherical pump (1). When the spherical pump (1) rotates in the forward direction, high-pressure oil is discharged through one oil feeding and discharging opening (121) formed in the cylinder cover (101) and enters a working cylinder of a double-piston-rod cylinder, oil in a non-working cylinder of the double-piston-rod cylinder flows back to the other oil feeding and discharging opening (121) formed in the cylinder cover (101), and double piston rods (7) stretch out to do work. When the spherical pump (1) rotates in the reverse direction, an oil circuit is reverse, and the double piston rods (7) are drawn back. Oil flowing from an overflowing channel (111) of the spherical pump (1) is communicated to an elastic oil reservoir (19), and is communicated to an oil discharging channel and an oil return channel of a main oil circuit through two check valves (15). The electro-hydraulic actuator has the advantages of being small in size, light in weight, high in running efficiency and low in energy consumption, and being capable of being used in exoskeleton suits and autonomous walking robots.