Energy demands are continually increasing as a result of population growth and industrialization, prompting the completion of new research to examine biochar-based catalytic pyrolysis of Spirulina plantensis (SP) microalgae for the generation of high-value chemicals in a microwave reactor. Biochar-based catalysts have excellent microwave absorption, a porous structure, and high catalytic activity, making them ideal for microwave-induced biomass pyrolysis. Initially, raw biomass, biochar, and Zn-BC were characterized based on XRD, FTIR, nitrogen adsorption-desorption and SEM-EDS analysis to determine the phases, functional groups, BET surface area and morphology, respectively. The thermogravimetric analysis results demonstrated the favourable impact of Zn-BC by displaying a drop in the reaction's temperature requirements. The kinetic study revealed that catalytic pyrolysis has a lower activation energy (27.62 kJ/mol) than non-catalytic pyrolysis (32.99 kJ/mol). FTIR measurement of the bio-oil indicated that at particular peak positions, intensity has changed or disappeared. The GCMS results revealed a significant reduction in the nitrogen-containing (19 %) chemicals at the same time increase in acidic chemicals for the catalytic bio-oil.