Nonlinear optical materials are the vital components of future photonic technologies as they can transfer and process data at the speed of light. However, the necessary prerequisites for a practical nonlinear optical material are very strict, and it is still a huge challenge to achieve the perfect balance among three critical parameters for nonlinear optics, including short cutoff edges, strong second-harmonic generation responses, and a suitable birefringence. Herein, via the introduction of the lone pair Pb2+ cations with stereochemical activity and the F- anions with the largest electronegativity into borate, a new fluorooxoborate PbB5O7F3 was obtained successfully. It exhibits a short cutoff edge (similar to 225 nm), a strong second-harmonic generation response (approximately 6 x KDP@1064 nm), and a large birefringence (cal. 0.12@1064 nm), achieving the optimal balance among the three critical parameters mentioned above for nonlinear optical applications in the short-wavelength region. The first-principles calculations were carried out to investigate the structure-property relationship of PbB5O7F3.