The utility model discloses a signal simulator for a power assembly electronic control development platform, which comprises a power component, a driving rotary shaft, a driving gear disk, a crankshaft gear disk, a driven rotary shaft, a driven gear disk, a camshaft gear disk, a crankshaft sensor and a camshaft sensor. The power component outputs rotary driving force; one end of the driving rotary shaft is coaxially fixed to an output shaft of the power component; the driving gear disk and the crankshaft gear disk are respectively arranged on the driving rotary shaft; the driven rotary shaft is oppositely parallel to the driving rotary shaft; the driven gear disk and the camshaft gear disk are respectively arranged on the driven rotary shaft; the driven gear disk is driven by the driving gear disk; and the crankshaft sensor and the camshaft sensor correspond to the crankshaft gear disk and the camshaft gear disk respectively and are used for outputting crankshaft speed signals and camshaft speed signals to an engine control unit on the power assembly electronic control development platform respectively. The signal simulator is capable of outputting stable crankshaft and camshaft speed signals to improve the operating stability of the power assembly electronic control development platform. On the basis, the utility model further provides the power assembly electronic control development platform applying the signal simulator.