A novel type of photonic crystal fiber (PCF) with low dispersion and high nonlinearity for four-wave mixing is proposed. This kind of fiber is composed of a solid silica core and a cladding with squeezed-hexagonal-lattice elliptical air-hole along the fiber length. Its dispersion and nonlinearity coefficient are investigated simultaneously by using full vectorial finite element method. Numerical results show that proposed highly-nonlinear low-dispersion fiber has the total dispersion as low as ±2.5 ps/(nm·km) over ultra-broad wavelength range from 1.43 μm to 1.8 μm by adjusting the structure parameters of photonic crystal fiber, such as the hexagonal squeezing ratio, the relative air hole size and the air hole ellipticity, and the corresponding nonlinearity coefficient is about 150 (W·km)-1 at 1.55 μm. The proposed PCF with low ultra-flattened dispersion, high nonlinearity and high birefringence can have important applications on the four-wave mixing.