A PET detection structure with application adaptability includes: at least two detector blocks and a detection ring for disposing the detector blocks. The at least two detector blocks are placed on the detection ring and surround a detected object in a manner of encirclement. The performance of each detector block includes inherent spatial resolution, time behavior, energy resolution, detection efficiency and maximum counting rate. The performance of the detector blocks are divided into a plurality of performance levels, and the performance level of one performance of at least one detector block of the at least two detector blocks is higher than the performance rate of the same performance of the other detector blocks.
