A circuit board of a multi-way flashing control box includes a control circuit to be connected electrically to a plurality of LED lamp strings and operable to activate and deactivate the LED lamp strings, and a plurality of connecting units, each of which is for connecting electrically the control circuit to a respective LED lamp string. Each of the connecting units includes a string terminal to be connected electrically to the respective LED lamp string, first and second conductive retainers connected electrically and respectively to the control circuit and the string terminal, and a circuit protection member having opposite ends clamped removably and respectively by the first and second conductive retainers such that the control circuit is connected electrically to the string terminal via the circuit protection member.