The invention discloses an onshore oscillating water column wave energy converter model testing device and a method, belonging to the hydraulic physical model testing field. In the oscillating water column wave energy converter model testing device, the front part of the device model body is connected with a front wall through a positioning screw. The upper part of the model body is sequentially provided with a wave height instrument, an air pressure sensor and a damping piece, wherein the air pressure sensor and the damping piece are connected through an air flow channel; the two sides of the model body are provided with shielding plates with shielding plate sandwiching layers to make the inner part of the model body form an air chamber structure with a good sealing effect. The lower part of the model body at the area opposite to the wave is provided with a ballast block; and the lower part of the model body at the area facing the wave is provided with an additional model through a clamping groove, and the clamping groove is provided with a water separating cover. The onshore oscillating water column wave energy converter model testing method comprises the following steps of: a testing preparation process, a testing process, an instrument sorting process and a data processing and analyzing process. The device of the invention is novel in design, simple in structure, good in integrity and applicable to wide working conditions. The testing device has the advantages of being high in test precision, convenient to operate in the testing process, high in testing efficiency, flexible in testing design and the like.