A method for manufacturing a high-strength galvanized steel sheet, the method comprising a first heating process of heating a steel sheet having a chemical composition containing, by mass%, C: 0.040% or more and 0.500% or less, Si: 0.80% or more and 2.00% or less, Mn: 1.00% or more and 4.00% or less, P: 0.100% or less, S: 0.0100% or less, Al: 0.100% or less, N: 0.0100% or less, optionally, by mass%, at least one selected from Ti: 0.010% or more and 0.100% or less, Nb: 0.010% or more and 0.100% or less, B: 0.0001% or more and 0.0050% or less, Mo: 0.01% or more and 0.50% or less, Cr: 0.60% or less, Ni: 0.50% or less, Cu: 1.00% or less, V: 0.500% or less, Sb: 0.10% or less, Sn: 0.10% or less, Ca: 0.0100% or less, and REM: 0.010% or less, and the balance being Fe and inevitable impurities to a temperature range of 800°C or higher and 950°C or lower in an atmosphere having a H 2 concentration of 0.05 vol% or more and 30.0 vol% or less and a dew point of 0°C or lower, a first pickling process of pickling the steel sheet which has been subjected to the first heating process in an oxidizing acidic aqueous solution and of rinsing the pickled steel sheet in water, a second pickling process of pickling the steel sheet which has been subjected to the first pickling process in a non-oxidizing acidic aqueous solution and of rinsing the pickled steel sheet in water, a second heating process of holding the steel sheet which has been subjected to the second pickling process in a temperature range of 700°C or higher and 900°C or lower in an atmosphere having a H 2 concentration of 0.05 vol% or more and 30.0 vol% or less and a dew point of 0°C or lower for 20 seconds or more and 300 seconds or less, and a process of performing a galvanizing treatment on the steel sheet which has been subjected to the second heating process, wherein the method further comprising an oxidizing process of heating the steel sheet to a temperature range of 400°C or higher and 900°C or lower in an atmosphere having an O 2 concentration of 0.1 vol% or more and 20 vol% or less and a H 2 O concentration of 1 vol% or more and 50 vol% or less after the second pickling process and before the second heating process. a first heating process of heating a steel sheet having a chemical composition containing, by mass%, C: 0.040% or more and 0.500% or less, Si: 0.80% or more and 2.00% or less, Mn: 1.00% or more and 4.00% or less, P: 0.100% or less, S: 0.0100% or less, Al: 0.100% or less, N: 0.0100% or less, optionally, by mass%, at least one selected from Ti: 0.010% or more and 0.100% or less, Nb: 0.010% or more and 0.100% or less, B: 0.0001% or more and 0.0050% or less, Mo: 0.01% or more and 0.50% or less, Cr: 0.60% or less, Ni: 0.50% or less, Cu: 1.00% or less, V: 0.500% or less, Sb: 0.10% or less, Sn: 0.10% or less, Ca: 0.0100% or less, and REM: 0.010% or less, and the balance being Fe and inevitable impurities to a temperature range of 800°C or higher and 950°C or lower in an atmosphere having a H 2 concentration of 0.05 vol% or more and 30.0 vol% or less and a dew point of 0°C or lower, Si: 0.80% or more and 2.00% or less, Mn: 1.00% or more and 4.00% or less, P: 0.100% or less, S: 0.0100% or less, Al: 0.100% or less, N: 0.0100% or less, optionally, by mass%, at least one selected from Ti: 0.010% or more and 0.100% or less, Nb: 0.010% or more and 0.100% or less, B: 0.0001% or more and 0.0050% or less, Mo: 0.01% or more and 0.50% or less, Cr: 0.60% or less, Ni: 0.50% or less, Cu: 1.00% or less, V: 0.500% or less, Sb: 0.10% or less, Sn: 0.10% or less, Ca: 0.0100% or less, and REM: 0.010% or less, and the balance being Fe and inevitable impurities to a temperature range of 800°C or higher and 950°C or lower in an atmosphere having a H 2 concentration of 0.05 vol% or more and 30.0 vol% or less and a dew point of 0°C or lower, a first pickling process of pickling the steel sheet which has been subjected to the first heating process in an oxidizing acidic aqueous solution and of rinsing the pickled steel sheet in water, a second pickling process of pickling the steel sheet which has been subjected to the first pickling process in a non-oxidizing acidic aqueous solution and of rinsing the pickled steel sheet in water, a second heating process of holding the steel sheet which has been subjected to the second pickling process in a temperature range of 700°C or higher and 900°C or lower in an atmosphere having a H 2 concentration of 0.05 vol% or more and 30.0 vol% or less and a dew point of 0°C or lower for 20 seconds or more and 300 seconds or less, and a process of performing a galvanizing treatment on the steel sheet which has been subjected to the second heating process, wherein the method further comprising an oxidizing process of heating the steel sheet to a temperature range of 400°C or higher and 900°C or lower in an atmosphere having an O 2 concentration of 0.1 vol% or more and 20 vol% or less and a H 2 O concentration of 1 vol% or more and 50 vol% or less after the second pickling process and before the second heating process.