  We demonstrate the existence of a topological chiral spin liquid in the
frustrated Shastry-Sutherland Heisenberg model with an additional spin
chirality interaction, using numerically unbiased exact diagonalization and
density matrix renormalization group methods. We establish a quantum phase
diagram where conventional phases, including dimer singlet, plaquette singlet,
N{\' e}el and collinear phase, can be clearly identified by suitable local
order parameters. Among them a $SU(2)_1$ chiral spin liquid emerges in the
highly frustrated region, which is unambiguously identified by two
topologically degenerate ground states, modular matrix, and characteristic
level counting in entanglement spectrum, featuring the same topological order
of $\nu=1/2$ bosonic Laughlin state. The phase boundaries among the different
orders are determined by the energy level crossing analysis and wave function
fidelity susceptibility.
