Well-formed and high-quality K2YbF5 microrods have been successfully synthesized by a simple and mild hydrothermal route for the first time. X-ray diffraction, scanning electron microscopy, energy dispersive spectrometer, and photoluminescence spectra were adopted to characterize the as-prepared samples. It is found that the as-obtained samples belong to orthorhombic system and exhibit spindle-like microrods morphology with length of about 7-10 mu m and diameter of about 3-6 mu m. The upconversion (UC) luminescence properties of K2YbF5:x %Y3+, 2 %Er3+ (x = 10, 30, 50, 70, 90) were systematically investigated. Under 980 nm laser excitation, the emission intensities and the corresponding output colors of K2YbF5:Y3+/Er3+ could be precisely manipulated by adjusting the Y3+ doping concentration. This study provides a great opportunity for exploring other complex fluorides with improved UC luminescence properties.