A novel high birefringence sensitivity photonic crystal fiber（PCF） for liquid sensing is designed to address the issues of complex structure, difficulty in manufacturing, and low sensitivity of existing PCF. The core of this optical fiber introduces two different sizes of elliptical air holes, and the cladding is composed of circular air holes of the same size arranged in a square-lattice. By combining finite element method with perfectly matched layer boundary conditions, the PCF is numerically simulated using COMSOL Multiphysics simulation software. Water is injected into the fiber core as a sensing liquid, and the birefringence, confinement loss, and sensitivity of the fiber are analyzed within the working wavelength range of 1.3~1.8 μm. The research results indicate that as the wavelength increases, the birefringence of the new PCF reaches the order of 10-2. At a wavelength of 1.3 μm, its sensitivity is as high as 54.4%, which is 1.1~2.5 times higher than the existing PCF.