According to the current Test Code for Stabilized Materials of Inorganic Binders in Highway Engineering (JTJ057-94), there are two main methods to determine lime dosage, one is EDTA titration (T0809-94), and the other is calcium electrode method (T08 10-94). According to the field laboratory conditions, EDTA titration is generally adopted, and its working sequence is as follows: (1) preparing suspension with standard mixture; (2) Titrate the standard suspension with EDTA standard solution to pure blue as the end point, and record the consumption of titration solution; (3) Establish a standard curve (also called working curve) with the lime consumption of the standard mixture as abscissa and the corresponding EDTA consumption as ordinate; (4) Make the field sample into suspension, titrate with EDTA standard solution, and record the consumption of the titrated solution; (5) According to the above consumption, the lime consumption on the corresponding standard curve is the lime consumption of the tested sample. However, at present, most site laboratories use the standard mixture of fresh lime soil to prepare the standard curve (also called working curve), which does not completely correspond to the daily engineering construction method. For lime stabilized soil and lime mixed soil that must be mixed once, the ash dosage can basically be truly reflected, but for on-site mixing method and secondary mixing method, the standard curve formulated by this method can not completely truly reflect the ash dosage. Therefore, it is difficult to accurately evaluate the compactness of mixture, and disputes often occur between contractors, supervisors and construction units in actual construction. Therefore, it is suggested that different EDTA standard curves should be established according to different construction techniques: ① The above standard curve prepared with newly mixed lime stabilized soil standard mixture is suitable for lime stabilized soil and lime mixed soil formed by one-time road mixing, and it is one of the acceptance standard curves that each site laboratory must do; (2) ②EDTA titration standard attenuation curve, which is suitable for lime dosage titration of lime mixed soil mixed with lime for the second time (the key point of this construction method is to mix 2-4% quicklime in the borrow pit for the first time, and then mix the remaining hydrated lime in the form of road mixing). The specific manufacturing method is as follows: a, 2-4% of quicklime is mixed in for the first time, and the quicklime is crushed with block ash and passed through 2.5%. B. After drilling for a period of time (usually about 7 days), add the remaining dose of hydrated lime and titrate the standard curve; C. Precautions: (1) The water content of the first lime mixed mortar should be 2-3 percentage points higher than the optimal water content; ⑵ Moisturizing should be adopted for health preservation; To sum up, only the indoor construction method close to the site can correctly and objectively reflect the ash dosage of the treated soil mixed with ash and effectively reflect its true compactness.