Oriented strand board (OSB) veneer technology and its performance have been widely studied in order to expand the range of OSB substrates. In this paper, OSB was a modified composite with boards as substrates, Myanmar old mahogany bark as the veneer material, and a cornstarch adhesive. Under such conditions, the optimal veneer technology was studied, and the index of the surface bonding strength and the veneer penetration rate were utilized in order to determine the performance. Two different processing technologies, cold pressing and hot pressing, were experimentally compared and hot pressing showed better performance. Subsequently, experiments were performed on the surface bonding strength and veneer penetration rate. The results show that the veneer performance of OSB is best when the unit pressure is 1.0 MPa, the hot-pressing temperature is 90 °C, and the hot-pressing time is 240 s. Furthermore, the magnitude of influence of the factors affecting the bonding strength is as follows: unit pressure > hot-pressing temperature > hot-pressing time. The research results have prospective significance for the performance optimization of OSB veneer technology.