The invention discloses an electronic ballast for setting and adjusting output power in fixed time via dial-up, belonging to the technical field of electronic ballasts. The electronic ballast comprises an EMI (Electro-Magnetic Interference) filter circuit, a bridge type rectification and PFC (Power Factor Correction) circuit, a step-down switch circuit, a dial-up switch, a single chip circuit, a PWM (Pulse-Width Modulation) control circuit, a full-bridge driving circuit, a full-bridge inverter circuit and a resonant ignition circuit, wherein the dial-up switch, the single chip circuit, the PWM control circuit, the step-down switch circuit, the full-bridge inverter circuit and the resonant ignition circuit are connected sequentially; the EMI filter circuit, the bridge type rectification and PFC circuit and the step-down switch circuit are connected sequentially; the full-bridge driving circuit is respectively connected with the single chip circuit and the full-bridge inverter circuit; and the step-down switch circuit is further connected with the single chip circuit. The electronic ballast has simple structure, small volume and low energy consumption, can conveniently set the output power and adjust the output power in fixed time, and is suitable for being used as an electronic ballast of a ceramic metal halide.