The microporous Si3N4 ceramic hollow fibres with highly asymmetric structure were prepared by a combined phase-inversion and sintering method for the first time. Rod-like β-Si3N4 grains with high aspect ratios were observed in both the sponge-like and finger-like layers, leading to the formation of a strong three-dimensional network, which could be beneficial for the mechanical properties. Hollow fibres with a porosity of 50% and a bending strength of 290MPa have been achieved. The hollow fibres could be modified from hydrophilic to hydrophobic via grafting with fluoroalkylsilane (FAS) on the fibre surface. While conducting desalination in a vacuum membrane distillation (VMD) process, the modified membranes exhibited satisfactory membrane distillation performance, promising for practical applications.