A finite Berry curvature dipole can induce a nonlinear Hall effect in which a charge current induces a second harmonic transverse electric voltage under time-reversal-symmetric condition. Here, we report the transport measurement of giant nonlinear Hall effect in twisted WSe$_2$ homobilayers as evidenced by the dominated second harmonic Hall voltage that scales quadratically with the injection current. Benefited from strain-induced symmetry breaking, the nonlinear Hall effects are measurable globally along all in-plane directions. At the half-filling of the hole moire superlattice band in twisted WSe$_2$ where interaction effects are strong, we observe a record high nonlinear Hall responsivity of 10$^{10}$ V W$^{-1}$. Our work demonstrates a new and highly tunable correlated system to achieve nonlinear Hall effect and provides potential device applications using artificially constructed van der Waals superlattices.
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