In this paper, the problem of waveform design for multiple-input multiple-output (MIMO) radar which deploys one-bit digital-to-analog converts (DACs) is investigated. To reach a good radiation property, we consider to minimize the integrated sidelobe to mainlobe ratio (ISMR) of the transmit beampattern via designing the one-bit transmit sequence. However, the resulting optimization problem, which consisted of quadratic fractional objective function and binary constraint, is NP-hard and difficult to solve directly. To this end, a continuous and differentiable function is first utilized to approximate the one-bit waveform. By doing so, the discrete constraint is automatically removed and hence a novel optimization problem will be recast. Leveraging on the Dinkelbach method, the reformulated problem is well solved with the closed-form solution. Numerical simulation results are utilized to demonstrate the effectiveness and superiority of the proposed method compared with some existing method.