A load device for planar solid oxide fuel cell stack comprises: a balance plate, a high-temperature compressed column, a load cell, an elastic member, an equalizing ring, and an actuator. The balance plate is disposed abutted against the fuel cell stack, and the high-temperature compressed column is disposed on the balance plate, and the load cell and the elastic member are arranged at a top portion of the high-temperature compressed column. The actuator, being placed on the equalizing ring, is used for providing a load to the equalizing ring, the load cell, the elastic member and the high-temperature compressed column Thereby, the load exerted by the actuator can be detected from the measurement of the load cell while the relationship between the load variation and performance of the SOFC stack can be read directly or transmitted to an external device for display.