The present invention discloses a voltage conversion circuit having self-adaptive mechanism. A control branch includes a first resistor coupled between a second power supply and a control terminal, and a switch circuit that is coupled between the control terminal and a ground terminal and receives an input voltage from an input terminal to generate a control voltage at the control terminal. A voltage-withstanding P-type transistor circuit of an output branch is coupled between the second power supply and the output terminal that generates an output voltage and is controlled by the control voltage. A voltage-withstanding N-type transistor circuit of the output branch is coupled between the output terminal and the ground terminal and is controlled by an inverted input voltage. When the input voltage is at a first power domain high/low state, the output voltage is at a second power domain high/low state.