Hakea trineura is a multi-stemmed shrub growing to high and forms a lignotuber. The branchlets and new leaf growth have flattened, brown, short soft silky hairs, or are smooth. The leaves grow on a petiole about long. They are narrowly elliptic to egg-shaped long by wide with three distinct longitudinal veins. The leaves narrow gradually to the apex ending either with a sharp point or rounded. The inflorescence consists of 60–80 greenish-yellow flowers on a smooth or with sparsely flattened soft hairs on a rachis up to long. The mid-green pedicel long and smooth. The deep yellow perianths are long and are smooth or with a few hairs when in bud. The styles are mid-green and the pistil long. Flowering occurs from May to September and the fruit are smooth, obliquely egg-shaped long by wide and slightly curved.
Hakea trineura is restricted to the Maryborough to Rockhampton area of Queensland. It grows in hilly eucalyptus woodland over hummock grasslands. It is a quick growing shrub in tropical areas.