The work aims to improve corrosion inhibition of corrosion inhibitor in high temperature acid liquor and meet requirement of high temperature well acidizing treatment. A new high temperature corrosion inhibitor HTCI-1 was obtained by compounding such additives as potassium iodide and potassium iodide in a newly synthesized pyridine quaternary ammonium salt. The corrosion inhibition was also tested by using high temperature and high pressure dynamic corrosion instrument HK-1, the corrosion mechanism was analyzed by performing electrochemical test, SEM, EDS and other tests. Tests showed that corrosion rate of N80 test block reached 24.53 g/(m2?h) and 23.72 g/(m2?h) provided with 160 ℃, 16 MPa, 20%HCl or mud acid (12%HCl+3%HF) and 3.0% mass concentration, meeting the first grade indicator in SY/T 5405—1996. Main cause of decrease in corrosion rate of the N80 steel sheet in high temperature acid liquor is that a dense layer of hydrophobic adsorption film forms on the surface of carbon steel as corrosion inhibitor molecules are absorbed onto carbon steel, which reduces the possibility of erosive ions contacting with steel surface, inhibits corrosion electrode reaction process and achieves the purpose of protecting metal at high temperature.