The invention provides a design method and a making and installing technique of a high-precision multifunctional fiber grating sensor. Under different installing modes, the sensor can realize the following properties: temperature sensitivity enhancement, temperature compensation strain sensitivity enhancement, temperature compensation pressure/tensile force measurement and temperature compensation pressure/tensile displacement simultaneous measurement. The design comprises the derivation of temperature and strain sensitivity enhancement coefficients, the derivation of temperature compensation during strain sensitivity enhancement sensing, the derivation of temperature compensation principle during other variable sensing and the derivation of interconversion between various forces. The making and installing technique comprises the design and encapsulation of a key nick, the selection method of sleeve material, the thermal expansion coefficient of which is the same as that of the environment, when the strain and displacement sensor is used, the fit usage of thermal grease in the temperature sensitivity enhancement sensor and the cascade mode internally providing temperature reference by using a multi-grid area.