膨化硝酸铵自敏化理论是膨化技术发明的核心，它是基于热点理论把微气泡植入硝酸铵炸药中。微气泡临界热点温度热力学计算为自敏化提供理论依据。与普通硝酸铵及珍珠岩相比较，微气泡在膨化硝酸铵内适当的分布为自敏化成功提供了有力的保证。

Self-sensitization theory of expanded ammonium nitrate (AN) is the key point of the present innovation .On the basis of heat points initiating mechanism of explosion, micro air bubble is embedded in explosive of expanded AN. the theoretical basis of self-sensitization is provided through calculation of critical heat point temperature of micro air bubble. Comparing expanded AN with common AN and pearlstone, the micro air bubble distribution and its regularity in expanded AN are given which provide powerful basis assurance for its success of self-sensitization.