The invention discloses a concrete unloading device for foundation construction of a wind power plant. The concrete unloading device is characterized by comprising a base part and an unloading part. The base part is composed of rebars and a frustum formed by welding steel plates. A rotary center shaft is arranged in the center of the frustum and provided with a snap ring and a snap ring pin. The end face, making contact with the frustum, of the rotary center shaft is provided with a bearing, and the snap ring is arranged on the upper portion of the bearing. The unloading part comprises an unloading trough and a bidirectional lifting regulating bolt. The two ends of the bidirectional lifting regulating bolt are connected with the rotary center shaft and the unloading trough correspondingly. The other point position of the unloading trough is connected with the rotary center shaft through a connection rod. The concrete unloading device for foundation construction of the wind power plant successfully achieves the aim that concrete is poured into bins continuously without a stop, the construction progress is accelerated, the construction cost is greatly lowered, universality is good, and the concrete unloading device is suitable for construction of fan foundations of different types.