The invention discloses an amplification, filtering and voltage-stabilizing type smartphone charging circuit which is characterized by being mainly composed of a transformer T, an operational amplifier P, a three-terminal regulator U, a triode VT1, a triode VT2, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a voltage-stabilizing diode D1, a voltage-stabilizing diode D2, a voltage-stabilizing diode D3 and a diode D4. The circuit of the invention is simple in structure and also low in cost; by using the circuit, damage to a phone battery when in charging can be reduced, so that the normal service life of the battery is improved to more than 10000h, namely prolonged by more than 25%, and thus great convenience is provided for smartphone users, and the circuit of the invention is applicable to popularization for use.