The invention relates to an L-beam piezoresistance type micro-accelerometer and a production method thereof, the micro-accelerometer comprises a supporting main framework body, an elastic beam, a weight block, cover plates and so on, which is characterized in that the elastic beam is shaped like L, a long arm of the L-shaped elastic beam is connected with a side frame of the supporting main framework body, the weight block is suspended in the middle of a supporting side frame body by the support of the L-shaped elastic beam, a short arm of the L-shaped elastic beam is connected with the top angle of the upper surface of the weight block; the upper and the lower surfaces of the supporting main framework body are bonded with the cover plates; the root part and the top end of the long arm of the L-shaped beam are respectively provided with a piezoresistor, and the two piezoresistors with the same resistance on the L-shaped beam constitute a bridge with the unilateral strain of a Wheatstone bridge. The micro-electron mechanical processing technology is adopted as the key production technology. The L-beam piezoresistance type micro-accelerometer can solve the problem that the existing piezoresistance type micro-accelerometer can not simultaneously meet the requirements of high sensitivity, small volume, low cost, small cross-interference and easy processing.