Abstract: The present disclosure provides a Cellulosimicrobium cellulans strain and use thereof in straw field composting, belonging to the technical field of microorganisms. In the present disclosure, the Cellulosimicrobium cellulans strain is named Cellulosimicrobium cellulans MC29-GFP, and is deposited in the China General Microbiological Culture Collection Center (CGMCC), with a deposit number of CGMCC No. 25013. The Cellulosimicrobium cellulans MC29-GFP can promote the compost decomposition of straw in field. The experimental results show that the Cellulosimicrobium cellulans MC29-GFP significantly increases activities of cellulase and peroxidase in the straw during the decomposition compared with Bacillus amyloliquefaciens SQR9, thereby achieving rapid decomposition.