In order to obtain the performance changes of the satellite-borne high-speed operational transimpedance amplifiers after a long period of operation in the on-board environment, experimental studies were conducted on the ionization total dose damage characteristics and change patterns of key characteristic parameters of three high-speed operational transimpedance amplifier chips with a gain bandwidth product greater than 1GHz. The irradiation tests were completed using high temperature accelerated evaluation on a ⁶⁰Co γ-ray source at a dose rate of 0.3~0.5Gy(Si)/s to the amplifier chip. The characteristics of key electrical parameters such as output bias, output noise and bandwidth of the amplifier chip before and after irradiation and before and after annealing at high temperature (85℃±6℃) were analysed after the tests, and the mechanisms causing the changes in the electrical parameters were discussed. The results show that after two rounds of 150Gy(Si) dose irradiation and high temperature annealing, the output bias and output noise level of the amplifier chip do not change significantly, the time domain impulse response was normal and the -3dB bandwidth was reduced by about 3%. Bandwidth is a radiation-sensitive parameter for the three high-speed operational transimpedance amplifier chips, and its variation is directly related to the positive charge build-up and interfacial state induced by ionising radiation at the SiO₂/Si interface. The irradiated chip is still capable of meeting the demands of high bandwidth test situations, with 150Gy(Si) being the cumulative dose for electrical parameters and functional qualification.