The maturation of GaN-based micro-nano structure growth methodologies have forged an innovative frontier in the fabrication of micro-nano GaN-based vertical cavity surface emitting lasers (VCSELs). This study delineates a sophisticated micro-nano VCSEL architecture founded on GaN axial heterostructures in the configuration of nanowires, incorporating Al0. 8Ga0. 2N/ In0. 2Ga0. 8N strain-compensated structures as top and bottom distributed Bragg reflector (DBR). Notably, the Al composition in the Al0. 8Ga0. 2 N layer far surpasses that in conventional structures, enhancing its effectiveness as an electron barrier, obviating the need for the electron blocking layer (EBL) traditionally employed as an electron-blocking mechanism. Furthermore, the influence of EBL on hole injection is meticulously examined. In pursuit of refining the hole injection efficiency of GaN-based VCSELs, a numerical model featuring EBL at distinct positions is formulated using commercial software PICS3D, followed by numerical simulations and analyses that delve into the intricate physical mechanisms. The results underscore that the integration of a strain-compensated DBR, comprised of Al0. 8Ga0. 2N and In0. 2Ga0. 8N, coupled with the elimination of EBL in traditional configurations, markedly enhances hole injection efficiency, thereby optimizing the optoelectronic performance of the device.