To reduce the loss caused by power imbalance between switched-mode power amplifier (SMPA) units of all-digital transmitters (ADTx), this paper proposes an all-digital transmitter structure with power equalization and harmonic elimination. Based on the third and fifth harmonic cancellation, this structure achieves output power equalization of SMPA by controlling the width of 3-level sub-pulses to be the same. Moreover, the equalization of each switch transistor is realized by outphasing method. Finally, the feasibility of the method is verified by simulation results. For different input signals with a carrier frequency of 200 MHz, the proposed structure achieves the same output power of each SMPA unit.