Aiming at the problems of large volume and low integration of conventional balanced photodetectors for microwave photonics applications, a miniaturized, high-isolation balanced photodetector array based on hybrid photoelectric package technology is designed. By integrating multiple balanced photodiode chips and their bias and matching circuits, the balanced photodetector function of 4 independent channels is realized. The average volume of each channel is only 588 mm3. In addition, a test system is set up to test the performance of the balanced photodetector array. The test results show that the response of each channel of the balanced photodetector array is greater than 0.9 A/W, the bandwidth of 3 dB is about 12 GHz, the channel consistency in the bandwidth range is better than ±0.43 dB, the common mode rejection ratio is greater than 30 dB, the channel isolation is greater than 50 dBc, and the saturated input optical power at 10 GHz is greater than 8.4 dBm.