A manufacturing method of a surface-treated Zn-Ni alloy electroplated steel sheet, comprising: step S1 of preparing a Zn-Ni alloy electroplated steel sheet comprising a steel sheet and a Zn-Ni alloy-plated layer in which a content of Ni formed on the steel sheet is 5 wt% to 20 wt%; step S2 of preparing an alkaline electrolytic solution in which 4 g/L to 250 g/L of potassium hydroxide, sodium hydroxide (NaOH), or both at the same time are added to distilled water; and step S3 of obtaining a surface-treated electroplated steel sheet by placing the Zn-Ni alloy electroplated steel sheet as an anode inside the alkaline electrolytic solution, and installing another metal sheet as a cathode, and applying 2 V to 10 V of an alternating or direct current for 10 to 30 seconds to conduct electrolytic etching such that a 3-point average value of an arithmetic average roughness Ra of a surface of the Zn-Ni alloy electroplated steel sheet reaches 200 nm to 400 nm, wherein a 3-point average value of a root-mean-square roughness Rq of the surface of the surface-treated Zn-Ni alloy-electroplated steel sheet after S3 of obtaining the surface-treated electroplated steel sheet is 290 nm to 600 nm, wherein a 3-point average value of a maximum roughness Rmax of the surface of the surface-treated Zn-Ni alloy-electroplated steel sheet after S3 of obtaining the surface-treated electroplated steel sheet is 2900 nm to 5000 nm, and wherein the arithmetic mean roughness Ra the root mean square roughness Rq and the maximum roughness Rmax are measured using a KOSAKA SE700 device, and cut-offs with λc, a filter filtering out small waveform vibrations generated from the surface, were set to 2.5 mm. step S1 of preparing a Zn-Ni alloy electroplated steel sheet comprising a steel sheet and a Zn-Ni alloy-plated layer in which a content of Ni formed on the steel sheet is 5 wt% to 20 wt%; step S2 of preparing an alkaline electrolytic solution in which 4 g/L to 250 g/L of potassium hydroxide, sodium hydroxide (NaOH), or both at the same time are added to distilled water; and step S3 of obtaining a surface-treated electroplated steel sheet by placing the Zn-Ni alloy electroplated steel sheet as an anode inside the alkaline electrolytic solution, and installing another metal sheet as a cathode, and applying 2 V to 10 V of an alternating or direct current for 10 to 30 seconds to conduct electrolytic etching such that a 3-point average value of an arithmetic average roughness Ra of a surface of the Zn-Ni alloy electroplated steel sheet reaches 200 nm to 400 nm, wherein a 3-point average value of a root-mean-square roughness Rq of the surface of the surface-treated Zn-Ni alloy-electroplated steel sheet after S3 of obtaining the surface-treated electroplated steel sheet is 290 nm to 600 nm, wherein a 3-point average value of a maximum roughness Rmax of the surface of the surface-treated Zn-Ni alloy-electroplated steel sheet after S3 of obtaining the surface-treated electroplated steel sheet is 2900 nm to 5000 nm, and wherein the arithmetic mean roughness Ra the root mean square roughness Rq and the maximum roughness Rmax are measured using a KOSAKA SE700 device, and cut-offs with λc, a filter filtering out small waveform vibrations generated from the surface, were set to 2.5 mm.