To cope with the flexibility from both load side and supply side, nuclear power generation should provide flexible operation services to improve its economic competitiveness. The prerequisite of flexible operation is the real-time realization of the operation point which is usually achieved by unit coordinated control finding the setpoints of nuclear power, coolant flow and feedwater flow to meet various load demand and keep key parameters within reasonable limits. Modular high temperature gas-cooled reactor (MHTGR) is typically a small reactor and adopt adjustable helium flow, graphite and once through steam generator (OTSG) as coolant, moderator, heat exchanger, respectively. The thermal hydraulic characteristics of MHTGR are of significant difference compared with that of pressurized water reactor (PWR). As a result, the coordinated control design for MHTGR plant is quite different from the PWR. In this paper, the feedwater flow and control rods are solely used to regulate the steam temperature and nuclear power, respectively. Moreover, the so-called dynamic matrix control (DMC) then is utilized to realize the load match for MHTGR thermal power, where the setpoint of helium flow is regarded as manipulated variables and the modular thermal power is regarded as controlled variables to be optimized. The effectiveness of the proposed method is then tested and verified by a hardware-in-loop simulation through a commercial distributed control system (DCS).