Small-pitch infrared detectors have become an important direction in the development of infrared detector technology. The preparation process level of indium bump, which connects the detector chip and the readout circuit chip, has become an important factor affecting the performance. The fabrication process of indium bump for infrared detectors with 10 μm pitch is introduced. The new process uses multiple indium film growth combined with ion-etching methods, finally prepares a 10 μm-pitch indium bump for infrared detector readout circuit (ROIC) with a height of 8 μm and a non-uniformity of less than 5%, which solves the problem of insufficient height when small-pitch indium bump is fabricated by the conventional process. The advantage is that there is no need to prepare the indium bump on the two chip ends, which simplifies the process. The result provides an idea for the preparation of indium bumps for smaller pitch infrared detectors in the future.