Purpose This paper aims to reduce part defects and improve ceramic additive manufacturing (AM). Selective laser melting (SLM) experiments were carried out to explore the effect of laser power and scanning speed on the microstructure, melting behaviour and surface roughness of cuprous oxide (Cu2O) ceramic. Design/methodology/approach The experiments were designed based on varying laser power and scanning speed. The laser power was changed between 50 W and 140 W, and the scanning speed was changed between 170 mm/s and 210 mm/s. Other parameters, such as scanning strategy, layer thickness and hatch spacing, remain constant. Findings Laser power and scan speed are the two important laser parameters of great significance in the SLM technique that directly affect the molten state of ceramic powders. The findings reveal that Cu2O part defects are widely controlled by gradually increasing the laser power to 110 W and reducing the scanning speed to 170 mm/s. Furthermore, excessive laser power (>120 W) caused surface roughness, cavities and porous microstructure due to the extremely high energy input of the laser beam. Originality/value The SLM technique was used to produce Cu2O ceramic specimens. SLM of oxide ceramic became feasible using a slurry-based approach. The causes of several part defects such as spattering effect, crack initiation and propagation, the formation of porous microstructure, surface roughness and asymmetrical grain growth during the SLM of cuprous oxide (Cu2O) are thoroughly investigated.