Neuromorphic technology provides a promising platform for driving the next wave of artificial intelligence. An emerging research topic is performing advanced functions in an ultra-compact neuromorphic device. Here we report an artificial neuron based on a novel threshold-switching double-gate MoS₂ transistor which can emulate the excitatory-inhibitory spatiotemporal integration neural functions. The neuron, featuring an ultra-compact physical configuration, provides a promising approach for constructing large-scale hierarchical neural network.