The invention discloses a space debris detecting device based on a thin film type solar cell array, comprising a detecting case having a top opening, a first layer of the thin film solar cell array, asecond layer of the thin film solar cell array, and a piezoelectric effect detecting layer. A first layer array and a second layer array are respectively formed by plating a single solar cell unit arranged in a grid pattern on a polymer film. The solar cell units of the two-layer array are sensitive to the sunlight of different bands respectively. The sunlight sensitive to the second layer (ie, bottom layer) of the solar cell array can penetrate the first layer of the solar cell arrays. According to the space debris detecting device based on the thin film type solar cell array, the structureis simple, the manufacturing cost is low, and the detection of the space debris is easy to be realized, and the size, speed, direction and quality data of the space debris can be obtained.