Nonclassical light fields with a property of strong antibunching are important resources for quantum information and quantum optics. Based on the quantum interference effect of nonlinear optics, a strong antibunching light can be obtained by superposing the squeezed vacuum state and the coherent state of a specific phase on an optical beam splitter. Squeezing degree and displacement can be independent adjustments for optimal antibunching. In this paper, combined with the parameters of the experiment system, we have theoretically studied the influence of the squeezing degree of the squeezed vacuum state and the amplitude of the coherence state on the generating of an antibunching light. Under the optimal displacement condition, analyzed the influence of the measurement of g20 of the antibunching light with system total efficiencies、background noises、Hanbury Brown-Twiss (HBT) and Double HBT measurement method. Discussed the value of g20 and average photon rate of the quantum state where the error is 0.