The use of 3D printing is becoming more and more popular, and new applications in extrusion and photopolymerization are being discovered every day. Due to the unidirectional action of the materials used, it is necessary to develop polyfunctional composites that provide a complex of extrusion and photopolymerization processes for 3D printing technology. The current problem of 3D printing application is the availability of ineffective composite materials with deteriorated mechanical and damping properties, which makes it difficult to use existing composite materials for application in 3D printing technologies. Therefore, the aim of this study was to create a biodegradable composite material based on polylactic acid and poly(3-hydroxybutyrate) reinforced with cellulose fibrils and plasticized with polyoxyethylene for possible application in extrusion, using the example of Maestro 3D printer. The study looked at mechanical, dynamic and thermal indicators. Except for the mechanical ones, all of the indicators tested out to be quite good. Thus, composite PLA: PHB (3:7) + 10% CFs demonstrated the highest glass transition temperature of 57 C. A 75% weight loss occurred at 373.58 C. In future, it is necessary to investigate alternative types of characteristics, modify the material's composition, or use it in applications where they are not critical. The scientific novelty of the work is the creation of a biodegradable composite material to study the properties of the composite material by extrusion for the purpose of application in 3D printing technologies.