There are some methods like steaming , solar exposure etc but solar sterilization is considered best that doesn't harm soil properties too much..

I think the best way to sterilization is improving the soil healthy and  microbial activity, provide the bacteria and microorganism in the soil a good condition and plant some cover crop mix with grass, always natural ways doing the best

In laboratory,  you can to use of ultraviolet irradiation for small amounts of uniformized soil in thin layersis could be on of the best way for sterilization of soil that have Lesser effect on soil properties.

You can autoclave the soil, but the protein compounds in the soil are distorted because you are over 60C degrees.

Is there any work comparing the changes in soil physico-chemical and biological properties in response to solarisation, steaming and autoclaving..

The goal of soil sterilization can be counter productive when no residue microbial life is left the vacuum left with allow unwanted microbials to take over. Rather than sterilization a type of augmenting of beneficial microbials and weakening pathogenic influence is the best course of action. Compared to drastic heat the idea of favoring beneficial microbes and lessening pathogen can be available by use of solarization of soil under plastic sheets and the incorporation of organic materials as amendments are an adjunct to this process. Another biological process of obtaining a soil fumigant effect would be biofumigation with a winter cover such as oil seed radish which residues produce dyanic compounds which reduce nematodes, weeds and pathogenic microbials. Compared to chemical fumigants and drastic heat treatment these methods are able to maintain positive biology and reduce toxicity and environmental issues. 

 thank you for your reply....

I want to test Phosphate solubilizing bacteria in simulated condition, so is it true that i sterilize soil ? 

I want to make a "reference soil" with distinct properties ....

Interesting quarry..and interesting work outlined below: 

The method of soil sterilization and soil type had significant effects on biomass P estimated in soils (P < 0.01). There were no significant differences between extracted biomass P at chloroform fumigation, autoclaving at 121°C for 0.5 h, and oven drying at 70°C for 48 h. However biomass P was significantly more extracted from soil by oven drying at 180°C for 2 h and by ultrasonification. Fixation of Pm in soil during the extraction period can reduce the precision of biomass P estimates. This effect was more obvious in biomass P determination by fumigation and oven drying at 70°C for 48 h. Biomass P determined by these methods and autoclaving had positive and significant correlations with soil sand contents, respectively due to long sterilization period and temperature. Ultrasonification released more P from these calcareous soils especially at the start of soil incubation. It released higher microbial P and reduced P sorption in soils; biomass P determined by this method compared to other methods had relatively higher correlations with fungi, glumales spore and P solubilizing bacteria numbers in soil.Source ; PLANT SOIL ENVIRON., 56, 2010 (4): 156–162..PDF enclosed for further reading..