Heterostructure field-effect transistors (hetero-FETs) are experimentally demonstrated, consisting of van der Waals heterostructure channels based on a 2D semiconductor. By optimally selecting the band alignment of the heterostructure channels, different output characteristics of the hetero-FETs were achieved. In atomically thin WSe2/MoS2 hetero-FET with staggered energy band, the oscillating transfer characteristic and negative transconductance were realized. With near-broken-gap alignment in the MoTe2/SnSe2 heterostructure channel, a superior reverse-biased current was obtained in the hetero-FETs, which can be analyzed as typical tunneling current. Our study on the hetero-FET-based atomically thin van der Waals heterostructure channel, provides significant inspiration and reference to novel heterostructure FETs.