The invention relates to the technical field of foundation bases, and relates to an uplift bearing capacity testing device for a miniature fiber bar uplift pile. According to the testing device, the upper portion of a first steel base plate is connected with a high-strength nut, the lower end of the first steel base plate is connected with a load sensor, the lower portion of the load sensor is connected with a second steel base plate, and the bottom of the second steel base plate is connected with a counter-force beam; jack base plates are placed on the two sides of a pile hole, the bottoms ofjacks are installed in the centers of the jack base plates, the tops of the jacks are tightly attached to third steel base plates, beam stools are placed on the jack base plates, and hooping bars andfiber bars in the pile hole are connected to form an uplift pile fiber bar cage; fiber bar lock heads and the fiber bars are anchored on an head-expanded high-strength drawing screw rod, displacementsensors are symmetrically arranged on the two sides of the pile top of the miniature fiber bar uplift pile, and the displacement sensors are fixedly arranged on a reference beam; and the two ends ofthe reference beam are correspondingly supported on buttresses. The testing device is simple to mount and high in operability, the safety and reliability are high, the device is not prone to be damaged, the device can be repeatedly used, the cost is low, and larger uplift bearing capacity can be obtained.