Abstract: A method of preparing a single-phase modified sodium hyaluronate gel, comprising preparing a sodium hyaluronate solution with a mass fraction between 5% to 15% in an alkaline condition at a pH value between 11 to 14, wherein the sodium hyaluronate has a molecular weight between 1.5 million to 4 million Daltons; adding a cross-linking agent to a solution of step (1), wherein the cross-linking agent and the sodium hyaluronate has a molar ratio between 9% to 15%; rapidly mixing for 20 to 40 minutes to form a gel; allowing to stand after subjecting to a water bath at constant temperature; dialyzing with a dialysis membrane to remove un-reacted cross-linking agent and hydroxide ion; homogenizing; and adding a mobile phase and mixing sufficiently to obtain a high viscosity stabilized single-phase modified sodium hyaluronate gel.