The invention discloses a dual 
optical path type scattered 
water quality turbidity measurement apparatus. The 
water quality turbidity measurement apparatus comprises a 
signal processing unit and a measurement chamber, wherein a 
light source is arranged in the measurement chamber, the 
turbidity measurement apparatus is characterized in that a semi-reflecting translucent mirror is arranged below the 
light source, a collimating lens is arranged below the semi-reflecting translucent mirror, a first 
detector is arranged in the measurement chamber, the 
light source is received by the first 
detector after being reflected by the semi-reflecting translucent mirror and then is transmitted to the 
signal processing unit, the light source is irradiated into a detected 
water sample through the collimating lens after being subjected to transmission by the semi-reflecting translucent mirror; a converge lens and a second 
detector are arranged in a direction vertical to a parallel light, light rays, scattered by 90 DEG by the detected 
water sample, of the parallel light are received by the second detector trough the convergence lens and are transmitted to the 
signal processing unit, the convergence lens and the second detector are arranged in the detected 
water sample, the collimating lens is arranged above the detected water sample, and the 
signal processing unit is used for processing received signals so as to obtain a turbidity value of the detected sample. The 
turbidity measurement apparatus disclosed by the invention is simple in structure, small in volume and relatively high in 
measurement precision.