A current sharing control strategy based on decoupled model predictive control (MPC) is proposed to address the issue of unbalanced phase current in three-phase interleaved parallel three-level DC-DC converters caused by parameter mismatches. Based on the topological equivalence of the converter using a virtual voltage source, the average state equation of the converter is established. An extended state observer is introduced to compensate for the coupling disturbance in the inter-phase current differences. Based on the decoupled nature of the control loops, a decoupled MPC approach with indirect control variables and normalized cost function is proposed. The proposed current sharing control strategy can take into account the control objectives of input voltage sharing and average output current tracking while realizing the inter-phase current sharing of the converter through independent optimization of multiple control links. Furthermore, the reduced-order equivalence of the decoupled inner current loop simplifies the design of the outer voltage loop control parameters. Finally, the effectiveness of the proposed current sharing control strategy is verified through experiments.