The invention relates to a machine capable of persistent power generation when only water needs to be supplemented during manufacturing and a power generation method thereof. The power density of the power generation of the machine is similar to that of a commercial alkaline fuel cell, and the cost of the power generation is the minimum relative to other fuel cells. Due to the fact that the power generation method is formed in combination with a new-found water hydrogen production method and a traditional hydrogen fuel cell technology, the name of the machine is water fuel cell hydrogen energy generator, short for JS generator or alkaline water generator. The generator has the characteristic that water is directly used for replacing hydrogen and air or oxygen as a fuel and an oxidant, and is characterized in that hydrogen or air does not need to be added, only pure water need to be added, and persistent power generation can be realized without consuming any other substance. The generator can be prepared into a mobile domestic generator, or is used for manufacturing various small and medium sized power stations, is particularly suitable for manufacturing fuel cell power vehicles, and is also particularly suitable for application of aerospaceplanes or submarines needing oxygen.