A method for generating a wireless charging alignment line on a mobile phone, applicable to a wireless charging device with a corresponding symbol, comprising: starting an application in the mobile phone and generating an operation screen, and placing the mobile phone on a wireless charging device; moving the mobile phone according to indication of the operation screen, and generating a first unchargeable line, a first preferred charging line, a second unchargeable line, and a second preferred charging line on the operation screen sequentially, the application calculating a median value according to the first unchargeable line, the first preferred charging line, the second unchargeable line, and the second preferred charging line position, and displaying an alignment line on the operation screen according to the median value. As such, the mobile phone can be aligned with the wireless charging device by the alignment line for optimal charging efficiency.