  We synthesized nonmagnetic PtBi$_2$ single crystals and observed a giant
linear magneto-resistance (MR) up to 684\% under a magnetic field $\mu_0H$ = 15
T at $T$ = 2 K. The linear MR decreases with increasing temperature, but it is
still as large as 61\% under $\mu_0H$ of 15 T at room temperature. Such a giant
linear MR is unlikely to be described by the quantum model as the quantum
condition is not satisfied. Instead, we found that the slope of MR scales with
the Hall mobility, and it can be well explained by a classical disorder model.
