The development of micro-fabrication and micro-assembly technology is indispensable for the future manufacturing of miniaturized, functional, and integrated devices. This paper proposes a planar micro-assembly technology to make the assembly of micro-objects easier. Firstly, delicate three-dimensional (3D) structures were fabricated on glass and silicon slice substrates using femtosecond laser two-photon polymerization (2PP). Secondly, transparent fluorescent scintillation ceramic powder, referred to as fluorescent powder, was assembled using a laboratory-made 3D moving heating micro-operator into a microstructure on a glass substrate, and this device is used to assemble the graphene powder into the microstructure on the silicon slice substrate. The fluorescence spectra and Raman spectra characterizations of the fluorescent powder and graphene powder in the microstructure were carried out by using excitation light at 405 nm and 532 nm, respectively. According to the above results, it can be concluded that the powder properties of the fluorescent powder and graphene powder assembled into the microstructure were not changed. The experimental device could not only assemble many micron-sized powder materials into hollow microstructures of arbitrary shape but also joined microstructures with different materials and characteristics to form a complex hybrid microstructure system.