Selective laser melting (SLM) has emerged as a versatile manufacturing method for complex metal components, offering high material utilization. 17-4PH stainless steel, which is known for its high strength and excellent corrosion resistance, is widely used in aerospace, biomedical, and mechanical manufacturing fields. However, the SLM process often results in microstructural features such as porosity and solute segregation, which significantly impact the wear and corrosion resistance of the produced components. Existing studies have primarily focused on the combined "solution heat treatment + aging" process, with limited research on individual solution or aging treatments. Furthermore, comparative studies on the effects of different heat treatment methods on wear and corrosion resistance remain insufficient. This study investigates the effects of three heat treatment methods—solution heat treatment (ST, 1 hour at 1040°C), aging treatment (AG, 1 hour at 480°C), and combined treatment (ST+AG, 1 hour at 1040°C followed by 1 hour at 480°C)—on the hardness, wear resistance, and corrosion resistance of SLM-manufactured 17-4PH stainless steel. The results reveal that aging treatment alone significantly enhances hardness, wear resistance, and corrosion resistance by optimizing the microstructure. Solution heat treatment improves microstructural uniformity and corrosion resistance but reduces wear resistance due to the complete transformation to a predominantly BCC structure. Combined treatment increases hardness but decreases wear and corrosion resistance due to precipitate formation. This study highlights the potential of aging treatment alone to enhance the performance of SLM-manufactured 17-4PH stainless steel, providing valuable experimental evidence for optimizing heat treatment strategies.