INTRODUCTION: The immunosuppressive tumor microenvironment (TME) of solid tumors inhibits most drug delivery system-based nanomaterials from achieving deep penetration in tumor tissue and interferes with T cell activity in terms of differentiation and exhaustion, which is becoming a critical therapy hurdle for solid tumors. Therefore, developing a therapeutic strategy with abilities of rapid establishment of tumor-targeted cells, elimination of immune obstacles, and enhanced active immunization is very important, while is still a big challenge. METHODS: A new strategy was explored to enhance immune therapy via the conjugation of microRNA155 (miR) to the surface of therapeutic monocyte with graphene quantum dots (GQDs). RESULTS: TME was reversed using surface-engineered monocyte immunotherapy via reprogramming pro-tumoral M2 TAMs into antitumor M1, and thus tumor elimination was dramatically enhanced. CONCLUSION: Such a surface-engineered monocyte immunotherapy has been demonstrated to be well tolerated to intravenous administration and bio-compatible, showing the potential to be extended for the solid tumor treatment.