Abstract: Reservoir is easily damaged by mud as the drilling cycle for fishbone horizontal wells is very long, and it is very difficult to solve the problem completely through acidization, so the paper presented this staged acidizing technology. 5-stage acidizing can be achieved by using a one-trip string containing a single-stage packer and 5 sand blasters which contain 4 sliding sleeves sand blasters. Through laboratory core corrosion test, the retarded mud acid and clean self-diverting acid were selected to form an acid system; by increasing the amount of acid and injection of liquid nitrogen, the stimulation effect is improved. This technology was used in Well Jing 52-H1Z and resulted in remarkable acid stimulation effect. The test results show that this acidizing technology is suitable for breaking and stimulating the complex fishbone horizontal wells.