Abstract: To address the in-situ manufacturing requirements for lunar regolith on the Moon's surface, a novel design for concentrated solar energy - flexible optical fiber transmission - powder bed fusion technology is presented. This device is intended for the melting and forming of lunar regolith, considering the specific constraints imposed by the lunar environment and the processing conditions required for regolith sintering. Two experimental setups are constructed to validate the feasibility of this approach: one outdoor for harnessing natural sunlight and another indoor using simulated solar conditions. Basaltic material from Jilin University (JLU) serves as a proxy for lunar regolith in these experiments. Outdoor tests utilize direct sunlight concentration, while indoor experiments mimic lunar surface conditions through the use of a solar simulator. Findings are revealed that at outdoor solar irradiance intensity of 636 W/m²and scanning speed of 1 mm/min, continuous lunar regolith sintering can be achieved. However, due to the variability and limitations of natural sunlight, stable long-term operation of the device outdoors cannot be maintained. Simulating the equivalent energy input from the lunar surface conditions using a solar simulator indoors, shows optimal performance when the system output reaches a peak energy flux density of 3.33 MW/m², with scanning speed of 30 mm/min and layer thickness of 2 mm. Under these conditions, the formed samples exhibit maximum apparent density, achieving apparent density of 2.16 g/cm³and compressive strength of 4.25 MPa. The sintering and forming technology explored in this study informs the development of in-situ construction strategies on the lunar surface, offering valuable insights for the design, calibration, and validation of payload devices intended for lunar missions.