Computer music production is an essential branch of computer technology in artistic creation. This is an interdisciplinary subject with information science and art. This paper proposes a creation model for digital music with first-order inhomogeneous first-order constant coefficient linear differential equations. This mode includes acoustic modes for waveform envelopes and bands. It has a straight-line mapping of phonetic patterns and rhythmic patterns. Then this paper uses the signal reconstruction principle and iterative extrapolation method to restore the signal in the frequency domain to obtain the simulated music. The experimental results show that this digital music creation model of inhomogeneous first-order constant coefficient linear differentiation can save a lot of labor costs. And this way can improve the audio quality and output effect. Compared with the undetermined factor method and the Laplace transform method in conventional advanced mathematics, the inhomogeneous first-order constant coefficient linear differentiation is more convenient in music composition.