Aiming at exploring the nature of dark energy (DE), we use forty-three observational Hubble parameter data (OHD) in the redshift range $0 < z leqslant 2.36$ to make a cosmological model-independent test of the $Lambda$CDM model with two-point $Omh^2(z_{2};z_{1})$ diagnostic. In $Lambda$CDM model, with equation of state (EoS) $w=-1$, two-point diagnostic relation $Omh^2 equiv Omega_m h^2$ is tenable, where $Omega_m$ is the present matter density parameter, and $h$ is the Hubble parameter divided by 100 $rm km s^{-1} Mpc^{-1}$. We utilize two methods: the weighted mean and median statistics to bin the OHD to increase the signal-to-noise ratio of the measurements. The binning methods turn out to be promising and considered to be robust. By applying the two-point diagnostic to the binned data, we find that although the best-fit values of $Omh^2$ fluctuate as the continuous redshift intervals change, on average, they are continuous with being constant within 1 $sigma$ confidence interval. Therefore, we conclude that the $Lambda$CDM model cannot be ruled out.
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