The disclosure relates to a low temperature polycrystalline silicon thin film transistor including: a substrate; a buffer layer formed on the substrate; a semiconductor layer formed on the buffer layer; a gate insulation layer formed on the buffer layer and the semiconductor layer; gates formed on the gate insulation layer; a dielectric layer formed on the gate insulation layer and the gates; a passivation layer formed on the dielectric layer; a first contact hole and a second contact hole formed respectively inside the passivation layer, the dielectric layer and the gate insulation layer, and sources ad drains formed respectively on the first contact hole and the second contact hole; the semiconductor layer being a low temperature poly silicon layer, and a reflective layer and/or an insulation layer disposed between the buffer layer and the semiconductor layer. The disclosure further relates to a manufacturing method for aforementioned thin film transistor.