Layout structure of digital-to-analog converter and layout method thereof

The invention discloses a layout structure of a digital-to-analog converter and a layout method thereof. The layout structure comprises a digital module, a switch array, a resistor module, a first metal layer and a second metal layer, the digital module and the switch array are arranged in parallel in a first direction; the resistor module comprises at least one resistor string; the first metal layer is used for wiring of first analog signal lines for connection between adjacent resistor units in the same resistor string and wiring of third analog signal lines for connection between different resistor strings and connection between a resistor module and a switch array; the second metal layer is used for wiring of digital signal lines connected between the digital module and the switch array; wherein the first direction is perpendicular to the second direction. According to the layout structure of the digital-to-analog converter, the resistor module, the digital module and the switch array are reasonably arran