The invention relates to a process of 
ammonium sulfite method 
caramel color with 
color index being more than or equal to 250000EBC. The process successively comprises the following steps: 
raw material metering and concentrating, a first time catalyst adding: adding 10 percent to 30 percent 
sulfite and 5 percent to 15 percent 
ammonium substances or 
ammonia substances or amine substances in the concentrated 
raw material, a first time of pressurized reaction, a second time catalyst adding: adding 0.01 percent to 0.05 percent 
metallocene catalyst into a material after the ending of the first time of reaction, a second time of pressurized reaction, blending, and metering and filling. According to the process, the 
ammonium sulfite method 
caramel color process is first used, after a 
reaction system generates a lot of heterocyclic rings and olefins, the 
metallocene catalyst is added to perform the second time of pressurized reaction, 
transition metal with positive valence in the 
metallocene catalyst is combined with 
electron of a 
monomer molecular to realize stereospecific 
coordination polymerization, esterification is avoided, reaction difficulty is decreased, 
carbon chain growth and conjugated 
double bond increase are performed, so as to obtain the 
caramel color with the 
color index being more than or equal to 250000EBC, and the caramel color is good in fluidity.