A solar tracker for photovoltaic power generation that is driven to trace solar light depending on a change of solar altitude and azimuth, comprising: a solar cell plate including one or more solar cell panels; an upper structure supporting the solar cell plate; a main post supporting the upper structure; a base bottom portion connected to the main post to support the upper structure; an altitude angle adjustment direct cylinder adjusting an altitude angle of the solar cell plate to correspond to an altitude of the sun that is seasonally changed; and an azimuth angle adjustment direct cylinder adjusting an azimuth angle according to time to correspond to a diurnal movement of the sun if the altitude angle is fixed by the altitude angle adjustment direct cylinder, characterized in that, an upper surface of the base bottom portion is fixed to one end portion of the main post, is connected to one end portion of the altitude angle adjustment direct cylinder through a hinge having a single degree of freedom, and is connected to one end portion of the azimuth angle adjustment direct cylinder through a locking type crisscross connector having two degrees of freedom, and a bottom surface of the upper structure is connected to the other end portions of the main post, the altitude angle adjustment direct cylinder, and the azimuth angle adjustment direct cylinder through locking type crisscross connectors respectively, and the locking type crisscross connector connected to the upper structure and the azimuth angle adjustment direct cylinder is configured to freely rotate about a length-direction shaft of the azimuth angle adjustment direct cylinder. wherein one shaft center of a mechanical shaft of the locking type crisscross connector that connects the main post with the bottom surface of the upper structure based on a state where the upper structure is horizontally maintained and one shaft center of a mechanical shaft of the locking type crisscross connector that connects the altitude angle adjustment direct cylinder with the bottom surface of the supper structure coincide with each other about the two mechanical shafts so as to form an azimuth angle rotary shaft, and the other shaft center of the mechanical shaft of the locking type crisscross connector that connects the main post with the bottom surface of the upper structure and one shaft center of a mechanical shaft of the locking type crisscross connector that connects the azimuth angle adjustment direct cylinder with the bottom surface of the upper structure coincide with each other about the two mechanical shafts so as to form an altitude angle rotary shaft that is at right angles to the azimuth angle rotary shaft. a solar cell plate including one or more solar cell panels; an upper structure supporting the solar cell plate; a main post supporting the upper structure; a base bottom portion connected to the main post to support the upper structure; an altitude angle adjustment direct cylinder adjusting an altitude angle of the solar cell plate to correspond to an altitude of the sun that is seasonally changed; and an azimuth angle adjustment direct cylinder adjusting an azimuth angle according to time to correspond to a diurnal movement of the sun if the altitude angle is fixed by the altitude angle adjustment direct cylinder, characterized in that, an upper surface of the base bottom portion is fixed to one end portion of the main post, is connected to one end portion of the altitude angle adjustment direct cylinder through a hinge having a single degree of freedom, and is connected to one end portion of the azimuth angle adjustment direct cylinder through a locking type crisscross connector having two degrees of freedom, and a bottom surface of the upper structure is connected to the other end portions of the main post, the altitude angle adjustment direct cylinder, and the azimuth angle adjustment direct cylinder through locking type crisscross connectors respectively, and the locking type crisscross connector connected to the upper structure and the azimuth angle adjustment direct cylinder is configured to freely rotate about a length-direction shaft of the azimuth angle adjustment direct cylinder. wherein one shaft center of a mechanical shaft of the locking type crisscross connector that connects the main post with the bottom surface of the upper structure based on a state where the upper structure is horizontally maintained and one shaft center of a mechanical shaft of the locking type crisscross connector that connects the altitude angle adjustment direct cylinder with the bottom surface of the supper structure coincide with each other about the two mechanical shafts so as to form an azimuth angle rotary shaft, and the other shaft center of the mechanical shaft of the locking type crisscross connector that connects the main post with the bottom surface of the upper structure and one shaft center of a mechanical shaft of the locking type crisscross connector that connects the azimuth angle adjustment direct cylinder with the bottom surface of the upper structure coincide with each other about the two mechanical shafts so as to form an altitude angle rotary shaft that is at right angles to the azimuth angle rotary shaft.